FRAME RELAY

Frame Relay merupakan layanan jaringan komunikasi data dengan teknologi Frame switching yang berkecepatan tinggi untuk menghubungkan satu atau beberapa lokasi ke berbagai lokasi tujuan (point to multi point) baik di dalam ataupun luar negeri pada waktu yang bersamaan. Dalam lalu lintas komunikasi yang padat, Frame Relay jauh lebih efisien daripada sirkit sewa (leased line) yang disediakan khusus untuk satu pelanggan (dedicated), yang umumnya hanya terpakai 10% sampai 20% dari kapasitas lebarpita (bandwidth)-nya. Dalam paket yang berisi data elektronik, masih dilengkapi dengan deteksi kesalahan, dan ada konfirmasi dari penerima yang berbentuk kode, apakah paket dapat diterima secara utuh. Dala paket data terdapat istilah frame (bingkai) yang berfungsi untuk menyatakan batas bingkai sebuah paket. Sedangkan batas frame sendiri ditandai dengan flag, sehingga data akan dibawa sepanjang jalur komunikasi dalam bentuk frame-frame. Berikut ini stuktur dari sebuah frame :

GFI = General Format Identifier
LCN = Logical Channel Number
LGN = Logical Channel Group Number
PKT TYPE ID = packet type identification
FCS = Frame check sequence
DLCI = data link connection Indentifier
C/R = Command/response field bit
(application specific-not modified by network)
FECN = Forward Explicit Congestion notification
BECN = Backward Explicit Congestion notification
DE = Discard Eligibility Indicator
EA = Address Extension
Gambar 1. (a) Struktur dasar frame, (b) Field informasi pada X.25 (c) Struktur frame pada Frame Relay, dan (d) Format header pada Frame Relay

Koneksi LAN to LAN dengan berbagai aplikasi voice, multimedia, video conference dan aplikasi berbasis client-server / telnet / terminal emulation dengan sentralisasi database yang mencakup :
1. File transfer
2. Email
3. Web Intranet
4. Data entry
5. Pengendalian persediaan
6. Payment point
7. Corporate Internet dedicated

Aplikasi transaksional dan interaktif yang mencakup:
1. Online antar cabang
2. Reservasi hotel/tiket pesawat

KEUNGGULAN LAYANAN :
1. Bandwidth minimum yang diperoleh digaransi melalui parameter Committed Information Rates (CIR)
2. Memperoleh garansi bandwitdh dan kelebihan bandwith yang fleksibel
3. Tersedia beragam media akses yang digunakan
4. Ragam pilihan kecepatan sesuai dengan kebutuhan pelanggan
5. Pelayanan aduan gangguan 24 jam sehari dan 7 hari seminggu.
6. Cakupan layanan di seluruh Indonesia dan 220 negara di dunia.

SPESIFIKASI TEKNIS :
1. Tingkat kehandalan tinggi dengan dukungan sistem transmisi Fiber Optic dan network yang handal
2. Lebih ekonomis untuk berbagai tujuan karena menggunakan satu saluran fisik untuk menghubungi ke berbagai tujuan (star)
3. Memungkinkan pengelolaan trafik data yang bersifat bursty
4. Keberagaman pilihan protokol komunikasi dan jenis aplikasi
5. Tingkat keamanan yang tinggi karena merupakan jaringan private

Verbs as Complements

Verbs that are always followed by the infinitive.

Some verbs can take another verb as the complement instead of a noun. Sometimes the verbs functioning as the complement mustbe in the infinitive (to + verb) and sometimes it must be in the gerund ( verb + ing) form.The following verbs are always followed by the infinitive if the complement is a verb.

agree, attempt, claim, decide, demand,

desire, fail, forget, hesitate, hope,

intend, learn, need, offer, plan,

prepare, pretend, refuse, seem, strive

ten, try, want, wish.


- The president will attempt to reduce inflation in the next four years.

- The soldiers are preparing to attack the village.

- Cinthya has agreed to act as a liason between the two countries.


Verbs that are always followed by the gerund.

Other verbs must alwaysbe followed by the gerund. These verbs include:

admit, appreciate, avoid, can’t help, consider,

delay, deny, enjoy, finish, mind,

miss, postpone, practice, quit, recall,

regret, report, resent, resist, resume,

risk, suggest,


- John admitted stealing the jewels.

- Would you mind not smoking in this office?

- Michael was considering that building in its present condition.


Note : These sentences are made negative by adding the negative particle not before the infinitive or gerund.

- John decided not to buy the car.

- We regretted not going to the party last night.

The following verbs can be followed by either the infinitiveor the gerund with no change in meaning.

begin, can’t stand, continue, dread, hate,

like, love, prefer, start.


- He started to study after dinner, OR, He started studying after dinner.

- Joan hates to ride her bicycle to school, OR, Joan hates riding her bicycle to school.


Verbs + prepositions followed by the gerund

approve of , be better of, count on, depend on,

give up, insist on, keep on, put off,

rely on, succeed in, think about, think of,

worry about.
The following expressions contain the preposition to. The word to in these expressions must not be confused with the to in the infinitive. These verb + preposition expressions must also be followed by the gerund.

object to, look forward to, confess to.


- Marry insisted on taking the bus instead of the plane.

- Fred confessed to stealing the jewels.

- Henry is thinking of going to France in August.

Adjectives, Nouns, and Pronouns

Adjectives + prepositions followed by the gerund

Accustomed to, afraid of, capable of, fond of,

Intent on, interested in, successful in, tired of.


- Jean is not capable of understanding the predicament.

- Alvaro is intent on finishing school next year.

- Craig is fond of dancing.


Nouns + prepositions followed by the gerund

choice of , excuse for, intention of, method for,

possibility of, reason for, (method of),


- George has no excuse for dropping out of school.

- There is no reason for leaving this early.

- Connie has developed a method for evaluating this problem.


Any time a preposition is followed directly by a verb, the verb will be in the gerund form.

- After leaving the party. Ali drove home.

- He should have stayed in New York instead of moving to Maine.


Adjective followed by the infinitive

anxious, boring, dangerous, hard,

eager, easy, good, strange,

pleased, prepared, ready, able*,

usual, common, difficult.

*able means the same as capable in many instance, but the grammar is very different. While able is followed by the infinitive, capable is followed by of + [verb + ing].

- These students are not yet able to handle such difficult problems\

- These students are not yet capable of handling such difficult problem.


Examples of adjectives followed by infinitive

- Muhammad is anxious to see his family.

- We are ready to leave now.

- It is difficult to pass this test.


Some verbs can be followed by either the infinitive or gerund, but the meaning changes.

stop, remember, forget.


- John stopped studying. {John is not going to study anymore}

- John stopped to study. {John stopped doing something in order to study}


Pronouns before the gerund or infinitive:

allow, ask, beg, convince, expect, instruct,

invite, order, permit, persuade, prepare, promise, remind, urge, want.


Subject + verb + complement form {pronoun / noun} + [to + verb]. . .

- Joe asked Marry to call him when she woke up.

- We ordered him to appear in count.

- You should prepare your son to take this examination.


However, before the gerund, a noun or pronoun must appear in the possessive form.

Subject + verb + possessive form {noun / pronoun} + [verb + ing]. . .

- We understand your not being able to stay longer.

- He regrets her leaving.

- We object to their calling at this hour.


Pronouns


Subject : a, you, she, he, it, we, you, they.

Complement : me, you, her, him, it, us, you, them.

Passive Adjective : my, your, her, his, its, our, your, their.

Possesive : mine, yours, hers, his, its, ours, yours, theirs.

Reflective : myself, yourself, herself, himself, itself, ourselves, yourselves, themselves.
Diposkan oleh aditha_citra's blog di 06:36

Exercises

Execrice :

1. This pen isn’t working. Please give me another. (singular)
2. If you’re still thirsty. I’ll make another pot of coffee.
3. This dictionary has a page missing. Please give me the other. (the last one)
4. He does not need those books. He needs the others. (all the remaining)
5. There are thirty people in he room. Twenty are from Latin America and the other are from other countries.
6. Six people were in the store. Two were buying meat. Another was looking at magazines. Another was eating a candy bar. The other were walking around looking for more food. (notice the verbs)
7. This glass of milk is sour. Another glass of milk is sour too.
8. The army was practicing its drills. One group was doing artillery. The other was practicing combat tactics.
9. There are seven student from Japan. The others are from Iran, and others are from other places.
10. We looked at four cars today. The first two were far too expensive, but the other one were reasonably priced.


Exercise : Simple Present and Present Progressive

1. Something smells very good.
2. We are eating dinner at seven o’clock tonight.
3. He practices the piano every day.
4. They are driving to school tomorrow.
5. I believe you.
6. Maria has a cold.
7. Jorge is swimming right now.
8. John hates smoke.
9. Jill always gets up at 6:00 A.M.
10. Jerry is mowing the lawn now.


Execrice : Simple Past Tense and Past Progressive

1. Gene was eating dinner when his friend called.
2. While Maria was cleaning the apartment, her husband was sleeping.
3. At three o’clock this morning. Eleanor was studying.
4. When Mark arrived, the Johnsons were having dinner, but they stopped in order to talk to him.
5. John went to France last year.
6. When the teacher entered the room, the students were talking.
7. While Joan was writing the report, Henry was looking for more information.
8. We saw this movie las night.
9. At one time, Mr. Roberts owned this building.
10. Joes was writing a letter to from the present perfect.


Exercise : Present Perfect and Simple Past

1. John wrote his report las night.
2. Bob has seen this movie before.
3. Jorge has read the newspaper already.
4. Mr. Johnson has worked in the same place for thirty-five years, and he is not planning to retire yet.
5. We haven’t begun to study for the test yet.
6. George went to the store at ten o’clock this morning.
7. Joan has travelled around the world.
8. Betty wrote a letter last night.
9. Guillermo called his employer yesterday.
10. We have not seen this movie yet.


Exercise : Past Perfect and Simple Past

1. The policeman read the suspect his right after he had arrested him.
2. After John had washed his clothes. He began to study.
3. George had waited for one hour before the bus came.
4. Maria entered the university after she had graduated from the community collage.
5. Jeanette washed the pipettes after she had completed the experiment.
6. Jane sent a letter to her university after she had received her scholarship check.
7. After the stewardesses has served launch to the passengers, they sat down.
8. The car had flipped ten times before eat landed on eats roof.
9. We corrected own paper after we had taken de quiz.
10. John had lived in Miami for one ear, when his parents came to visit.

Keamanan Jaringan

Beberapa Ancaman dan Serangan
• Tujuan utama dengan adanya keamanan adalah untuk membatasi akses informasi dan sesumber hanya untuk pemakai yang memiliki hak akses.
• Ancaman keamanan:
o Leakage (Kebocoran) : pengambilan informasi oleh penerima yang tidak berhak
o Tampering : pengubahan informasi yang tidak legal
o Vandalism (perusakan) : gangguan operasi sistem tertentu. Si pelaku tidak mengharap keuntungan apapun.
• Serangan pada sistem terdistribusi tergantung pada pengkasesan ke saluran komunikasi yang ada atau membuat saluran baru yang menyamarkan (masquerade) sebagai koneksi legal
• Penyerangan Aktif, Secara aktif memodifikasi komunikasi atau data
o Pemalsuan atau pengubahan Email
o TCP/IP Spoofing

Beberapa Metode Penyerangan
• Eavesdropping, mendapatkan duplikasi pesan tanpa ijin
• Masquerading, Mengirim atau menerima pesanmenggunakan identitas lain tanpa ijin mereka
• Message tampering,
o Mencegat atau menangkap pesan dan mengubah isinya sebelum dilanjutkan ke penerima sebenarnya. “man-in-the-middle attack” adalah bentuk message tampering dengan mencegat pesan pertama pada pertukaran kunci enkripsi pada pembentukan suatu saluran yang aman. Penyerang menyisipkan kunci lain yang memungkinkan dia untuk mendekrip pesan berikutnya seelum dienkrip oleh penerima
• Replaying, menyimpan pesan yang ditangkap untuk pemakaian berikutnya.
• Denial of Service, membanjiri saluran atau sesumber lain dengan pesan yang bertujuan untuk menggagalkan pengaksesan pemakai lain

Keamanan Transaksi Elektronik
Keamanan sangat dibutuhkan pada kebanyak transaksi
• E-commerce
• Banking
• E-mail

Transaksi elektronik dapat aman jika dilindungi dengan kebijakan dan mekanisme keamanan. Contoh : Pembeli harus dilindungi terhadap penyingkapan kode credit number selama pengiriman dan juga terhadap penjual yang tidak bersedia mengirim barang setelah menerima pembayaran. Vendor harus mendapatkan pembayaran sebelum barang dikirim, sehingga perlu dapat memvalidasi calon pembeli sebelum memberi mereka akses

Kebijakan dan Mekanisme Keamanan
• Pemisahan antara kebijakan dan mekanisme keamanan akan membantu memisahkan kebutuhan implementasinya
o Kebijakan menspesifikasikan kebutuhan
o Mekanisme menerapkan spesifikasi kebijakan tersebut
• Berdasar spesifikasi dari OSI, sebuah layanan (kebijakan) keamanan meliputi :
o Access Control, Perlindungan terhadap pemakaian tak legak
o Authentication, Menyediakan jaminan identitas seseorang
o Confidentiality (kerahasiaan), Perlindungan terhadap pengungkapan identitas tak legak
o Integrity, Melindungi dari pengubahan data yang tak legak
• Untuk mencapai layanan keamanan tersebut, mekanisme-mekanisme yang dapat diterapkan :
o Enkripsi
 Digunakan untuk menyediakan kerahasiaan, dapat menyediakan authentication dan perlindungan integritas
o Digital Signature
 Digunakan untuk menyediakan authentication, perlindungan integritas, dan non-repudiation
o Algoritma Checksum/Hash
 Digunakan untuk menyediakan perlindungan integritas, dan dapat menyediakan authentication
o Satu atau lebih mekanisme dikombinasikan untuk menyediakan security service

Berikut adalah contoh program yang dapat menghasilkan kunci Public/Private Key dengan menggunakan algoritma RSA :

import javax.net.*;
import javax.net.ssl.*;
import java.security.*;
public class getPublicPrivateKey {
public static void main(String[] args) {
try {
//1024-bit Digital Signature Algorithm (DSA)
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
keyGen.initialize(1024);
KeyPair keypair = keyGen.genKeyPair();
PrivateKey privateKey = keypair.getPrivate();
PublicKey publicKey = keypair.getPublic();
System.out.print("Public Key : " + publicKey);
System.out.print("Private Key : " + privateKey);
// Generate a 576-bit DH key pair
keyGen = KeyPairGenerator.getInstance("DH");
keyGen.initialize(576);
keypair = keyGen.genKeyPair();
privateKey = keypair.getPrivate();
publicKey = keypair.getPublic();
System.out.print("Public Key : " + publicKey);
System.out.print("Private Key : " + publicKey);
// Generate a 1024-bit RSA key pair
keyGen = KeyPairGenerator.getInstance("RSA");
keyGen.initialize(1024);
keypair = keyGen.genKeyPair();
privateKey = keypair.getPrivate();
publicKey = keypair.getPublic();
System.out.print("Public Key : " + publicKey);
System.out.print("Private Key : " + privateKey);
}catch (java.security.NoSuchAlgorithmException e) {}
}
}

Digital Signature
• Didasarkan pada suatu ikatan tanda (yang tak dapat dirubah) ke suatu pesan atau dokumen yang hanya diketahui oleh si penandatangan.
• Hal ini dapat dicapai dengan cara mengenkrip sebuah pesan terkompresi (digest) dengan menggunakan private key
• Digest memiliki ukuran yang tetap yang dihasilkan dari sebuah secure digest function.


Contoh ilustrasinya :
• A ingin menandatangani dokumen M, sehingga penerima dapat yakin bahwa M adalah berasal dari A.
• A menghitung digest dokumen dengan fungsi Digest(M).
• A mengenkrip digest dengan private keynya, dan ditambahkan ke M, sehingga menghasilkan {Digest(M)}KApriv.
• B menerima dokumen tersebut dan mengambil M dan menghitung Digest(M).
• B mendekrip dengan {Digest(M)}KApriv menggunakan KApub dan membandingkan isinya dengan hasil perhitungan Digest(M). Jika sama, tandatangan adalah valid.

Televisi Digital

Teknologi Digital Arah perkembangan teknologi komunikasi nantinya akan menuju era komunikasi digital. Untuk mencapai era itu maka akan terjadi konversi dari komunikasi analog ke digital. Perbedaan keduanya adalah, teknologi analog cara kerjanya adalah dengan mengubah gelombang (secara fisik) menjadi sinyal elektrik, sinyal ini bersifat berkelanjutan (continous) baik amplitudonya maupun periodenya. Sedangkan teknologi digital bersifat tidak berkelanjutan (un continous), sinyal yang dikiramkan on/off. Sistem digital menggunakan serentetan angka yang merepresentasikan informasi.
Konversi Analog ke Digital Sistem digital menggunakan bahasa yang biner. Sistem ini menggunakan dua angka, 1 dan 0, yang disusun dalam kode yang berbeda, untuk menyampaikan informasi. Untuk mengubah sinyal analog menjadi digital digunakan Pulse Code Modulation (PCM) yang bisa mencoding sinyal analog untuk kemudian diubah menjadi digital. Sinyal analog dapat diubah menjadi bentuk digital dengan menggunakan analogto- digital converter (ADC). Ketika kode informasi tersebut disiarkan, bentuk digital itu bisa diubah menjadi bentuk analog yang asli dengan digital-to-analog converter (DAC) agar sinyal ini bisa dicara oleh teknologi analog. ADC dan DAC adalah jembatan antara sistem analog dan digital.
Frekuensi tv digital, secara teknis pita spektrum frekuensi radio yang digunakan untuk televisi analog dapat digunakan untuk televisi digital. Perbandingan lebar pita frekuensi yang digunakan teknologi digital adalah 1:6. Artinya apabila teknologi analog memerlukan lebar pita 8 MHz untuk satu kanal transmisi, maka pada tenologi digital dengan lebar pita yang sama dapat memancarkan sebanyak 6 hingga 8 kanal transmisi menggunakan teknik multipleks. Penyelenggaraan televisi digital memanfaatkan spectrum dalam jumlah besar, dimana menggunakan lebih dari satu kanal transmisi. Penyelenggara berperan sebagai operator jaringan dengan mentransmisikan program stasiun televisi lain secara terrestrial menjadi satu paket layanan.
TV digital memiliki hasil siaran dengan kualitas gambar dan warna yang jauh lebih baik dari yang dihasilkan TV analaog. Sistem televisi digital memungkinkan pengiriman gambar yang jernih dan stabil meskipun alat penerima siaran berada dalam kondisi bergerak dengan kecepatan tinggi. TV digital memiliki kualitas siaran berakurasi dan resolusi tinggi. Teknologi digital memerlukan tersedianya kanal dengan laju sangat tinggi mencapai Mbps untuk mengirimkan informasi berkualitas tinggi.

OTHERS, THE OTHERS, & ANOTHERS

OTHERS, THE OTHERS, & ANOTHERS

Kata other, another, dan others dapat diartikan dengan : yang lain atau lainnya. Ketiga kata tersebut sangat mudah membingungkan. Maka untuk menentukan bagaimana menggunakannya dengan tepat masing-masing kata itu harus diperhatikan empat hal.

1. Jika kata itu singular (tunggal) atau plural (jamak).
2. Jika kata itu definite –the- (tentu) atau indefinite –a- (tak tentu)
3. Jika kata itu berfungsi sebagai adjective yang menerangkan noun atau senantiasa bersama dengan noun.
4. Jika kata itu berfungsi sebagai pronoun yang dapat berdiri sendiri.

Perhatikanlah contoh-contoh berikut :
a. I have another (adj.) book
b. I have another (pron.)

“Perhatikan bahwa another digunakan hanya untuk menunjuk kepada an indefinite (tak tentu). Dan dengan benda tunggal (singular)”

c. I have other (adj.) books.
d. I have others. (pron)
e. I have the other book (adj.)
f. I have the other (pron.)
g. I have the other books (adj.)
h. I have the others (pron).

“Perhatikan bahwa Others hanya digunakan sebagai plural pronoun yang tidak bersama dengan noun(dapat berdiri sendiri). Sedangkan other dapat digunakan untuk semuanya”

i. I have three books, two are mine. The other book is yours. (The others is yours).
j. I have three books, one is mine. The others are yours. (The others are yours).
k. If you are still thirsty, I’ll make another pot of coffee.


Example :

OTHER -- the singular form. The word refers to something that is different from something else. For instance, Director A makes a movie based on a famous novel. Director B makes a different movie based on the same novel.

Luke: "Did you like Director A's movie?"
Ted: "Yes, but I liked the OTHER version much better."

Luke: "What do you think of my new wrist watch?" [On his right wrist.]
Ted: "I think you should wear it on your OTHER wrist."

Two senators write two different pieces of legislation about the same topic. "I like Senator Luke's legislation, but the OTHER one will probably be approved."

So, when we use the singular word "other," we are actually referring to something different from something else: X is fine, but I think the OTHER ["Y"] is more acceptable.

*****

OTHERS -- the plural form, for more than one "other"

Some essays are easy to read; OTHERS are much more difficult.

Many people chose to vote in the election. OTHERS simply stayed at home, not interested in voting at all. [OTHERS clearly indicates the "different" or "non-voting" people.]

*****

THE OTHERS -- same as above, but used in cases where the article "the" is necessary.

Luke: "Would you like to have THESE shirts?"
Ted: "No, I think THE OTHERS look more presentable."

The "chosen" people lived in the wealthy homes; all THE OTHERS lived in very poor houses. ["The others" in this example means "the people who are NOT wealthy" or THE OTHERS.]

*****

ANOTHER -- The dictionary definition is this: "different or distinct from the one first considered" OR "additional" OR "later."

Different or distinct --

Luke: "Are you going to write your essay about global warming?"
Ted: "I had thought I would, but I have changed my mind and will write on ANOTHER topic."

Additional --

Luke: "Did you get enough to eat?"
Ted: "No, I think I'll have another piece of pie."

Later --

Luke: "Are you taking a trip this weekend?"
Ted: "I think I'll wait until ANOTHER time."

*****

Simple Present – Present Progressive

Present Progressive

Notes:

1. The written lesson is below.
2. Links to quizzes, tests, etc. are to the left.

The present progressive is formed by combining the verb "to be" with the present participle. (The present participle is merely the "-ing" form of a verb.)

I am studying.
I am studying with María.

In English, present progressive can be used to describe what is happening now, or what will happen in the future.

I am studying now.
I am studying with María tonight.

In Spanish, the present progressive is only used to describe an action that is in the process of taking place. It is not used for future actions.

I am studying now.
(use present progressive)
I am studying with María tonight.
(do not use present progressive)

To form the present progressive in Spanish, combine a form of "estar" with the present participle.

Estoy hablando.
I am speaking.
Juan está comiendo.
John is eating.
María está escribiendo una carta.
Mary is writing a letter.

In order to form the present progressive, you must know how to conjugate the verb estar, and how to form the present participle. You already know how to conjugate the verb estar:

estar
estoy
estás
está
estamos
estáis
están

To form the present participle of regular -ar verbs, add -ando to the stem of the verb.

hablar: hablando
(hablar - ar + ando)
trabajar: trabajando
(trabajar - ar + ando)
estudiar: estudiando
(estudiar - ar + ando)

To form the present participle of regular -er and -ir verbs, add -iendo to the stem of the verb.

comer: comiendo
(comer - er + iendo)
hacer: haciendo
(hacer - er + iendo)
vivir: viviendo
(vivir - ir + iendo)
escribir: escribiendo
(escribir - ir + iendo)

To form the present participle of -ir stem changing verbs, change e:i and o:u in the stem, and then add -iendo to the stem of the verb.

servir: sirviendo
pedir: pidiendo
decir: diciendo
dormir: durmiendo
morir: muriendo
poder: pudiendo

Sometimes when forming the present participle it is necessary to change the spelling of a word so that it agrees with the way it is pronounced. We call this an "orthographic" change. Here are some common examples:

caer: cayendo
creer: creyendo
huir: huyendo
ir: yendo
influir: influyendo
oír: oyendo
traer: trayendo
leer: leyendo
seguir: siguiendo

The following examples illustrate the rules for forming the present participle.

hablar: hablando (-ar)
comer: comiendo (-er)
vivir: viviendo (-ir)
decir: diciendo (e:i)
dormir: durmiendo (o:u)
leer: leyendo (orthographic)
seguir: siguiendo (orthographic)

To form the present progressive, simply conjugate the verb estar to agree with the subject of the sentence, and follow it with the present participle.

Juan está comiendo pan.
John is eating bread.
María y Carmen están hablando con nosotros.
Mary and Carmen are speaking with us.

Remember, only use the present progressive for actions that are "in progress." Compare the uses of the present indicative with the uses of the present progressive.

Estudio español. (Present Indicative)
I study Spanish.
I am studying Spanish (these days).
I do study Spanish.
Estoy estudiando español. (Present Progressive)
I am studying (right now, at this moment) Spanish.

It is important to remember that you would never use the present progressive to say something like "We are going to Spain this summer." Use present progressive only for actions that are "in progress."

Let's add two more verb flashcards: one for present progressive and one for practice in forming the present participle:

Verb Flashcards
Complete List

Present Progressive
estar + present participle
I am speaking (right now, at this moment)
Never use present progressive for something that will occur in the future.

Present Participle (-ando, -iendo, yendo)

hablar - hablando (-ar)
comer - comiendo (-er)
vivir - viviendo (-ir)
decir - diciendo (e:i)
dormir - durmiendo (o:u)
leer - leyendo (orthographic)
seguir: siguiendo (orthographic)

Simple Present

Ada beberapa penggunaan dari simple present tense, yaitu :
untuk menyatakan kegiatan yang berulang untuk menyatakan generalisasi atau kegiatan yang biasa berlangsung. Untuk menyetakan kegiatan saat ini. Untuk lebih jelasnya perhatikan penjelesan di bawah ini

1. Repeated Actions (Kegiatan berulang)
Simple present dapat digunakan untuk menyatakan gagasan atau kegiatan yang dilakukan sering dilakukan berulangkali seperti bangun tidur, atau kebiasaan seperti berolahraga, jadwal pemberangkatan kendaraan dan lain sebagainya, kegiatan tersebut dapat berupa kebiasaan, hobby, kegiatan sehari-hari, jadwal, dan juga kebiasaan yang selalu tidak dilakukan.

Dari gambar diatas tanda silang warna biru adalah kejadian yang dilakukan, jadi kejadian tersebut selain dilakukan saat ini (persent) juga dilakukan pada waktu lampau (past) dan yang akan datang (future)

EXAMPLES:

• I play tennis.
• She does not play tennis.
• The train leaves every morning at 8 am.
• The train does not leave at 9am.
• She always forgets her purse.
• He never forgets his wallet.
• Every twelve months, the Earth circles the sun.
• The sun does not circle the Earth.

2. Menyatakan Kebenaran atau keadaan yang umum (Facts or Generalizations)

Simple Present dapat juga digunakan untuk mengekspresikan suatu kejadian yang benar pada masa lampau, sekarang maupun yang akan datang, misalnya matahari terbit dari barat, satu jam 360 menit dan lain sebagainya. Selain itu Simple Present juga digunakan untuk menyatakan generalisasi (keadaan yang umum) terhadap pikiran orang, misalnya orang batak suka musik, burung mempunyai sayap dan lain sebagainya
Perhatikan gambar berikut untuk lebih jelasnya
.

EXAMPLES:

• Cats like milk.
• Birds do not like milk.
• Jakarta is in Indonesia
• Surabaya is not in the United Kingdom.
• Windows are made of glass.
• Windows are not made of wood.
• Jakarta is a small city. (It is not important that this fact is untrue.)

3. Keadaan Sekarang Now (Non-Continuous Verbs)

Simple Present digunakan juga untuk menyatakan kegiatan yang berlangsung maupun tidak berlangsung saat ini secasra spontan. Namun hanya bisa digunakan dengan Non-continuous Verbs dan Mixed Verbs.

EXAMPLES:

• I am here now.
• She is not here now.
• He needs help right now.
• He does not need help now.
• He has a car.

Diterjemahkan dari : englishpage.com

PRESENT artinya adalah kini, sekarang.
Rumusnya:
Positif: S + V1 (s/es)
Negatif: S + DO/DOES + NOT + V1
Tanya: DO/DOES + S + V1

Contoh Kalimat Positif:

• I drink coffee
• She drinks coffe
• We drink coffee

Ya, sengaja pelajaran Tense bahasa inggris ini dibuat simple saja agar cepat faham. Anda perlu mengembangkannya sendiri misalnya dengan membuat 100 contoh sendiri. Pasti Anda perlu kamus juga, karena belajar tenses lalu mentok dengan suatu kata kerja maka biasanya tidak jadi, hehe..

Cara Membaca Rumus:

S artinya Subject, V1 artinya Verb1 atau kata kerja bentuk pertama. Garis miring artinya ya Atau dong!.

Kapan pakai S atau ES dan kapan tidak?
Kalau Subjectnya He, She, It, John, Mufli, Ellen atau Orang ketiga TUNGGAL maka kata kerjanya tambah S atau ES. Tidak sembarang tambah S atau ES juga nih, ada daftarnya. Daftarnya itu bayak sekali.

Di atas tadi ada istilah Orang Ketiga Tunggal, maksudnya gini: Orang ketiga adalah orang yang kita bicarakan, yang kita omongin. Sedangkan orang pertama ya yang bicara. Orang kedua lawan bicara. Tunggal ya satu. Jadi orang ketiga tunggal adalah orang yang kita bicarakan dan satu saja dia itu. Misalnya kita berdua ngomongin John Scoping. Yang ngomong saya, yang dengar Anda, yang dibicarakan John Scoping (orang ketiga tunggal).

John Scoping belajar Tenses.
John Scoping learnS english.

Tidak bisa LearnES, mengapa? ya memang begitu!. Tetapi yang ini malah tambah ES:

John Scoping goES to School (tambah ES).

Kalimat Negatif Present Tense

Bentuk Negatif, artinya menyatakan TIDAK. Maka sesuai rumus Present Tense, setelah SUBJECT ditambah DO atau DOES, baru NOT, lalu tambah kata kerja bentuk pertama tanpa S atau ES lagi. S atau ES nya dimana? Sudah di doES tadi.

Untuk I, WE, YOU, THEY tambah DO
Untuk SHE, HE, IT, Mufli, Ellen tambah DOES

I do not drink coffee.
She does not drink coffee.
John Scoping does not learn english.

Coba perhatikan She does not drink coffee. Drink nya tidak pake S lagi, pindah ke doES. Biasakan saja, Present Simple Tense ini sepertinya rumit tetapi kalau faham maka enak banget. Ulangi saja baca dari atas 10 kali lagi, biar meresap benar, hehe.. Bikin juga 10 contoh Anda sendiri dengan kata kerja yang berbeda. Yes, belajar bahasa Inggris tak boleh manja, harus aktif, baru akan bisa.

Kalimat Tanya Present Tense

Kalimat tanya untuk Present Tense sesuai rumus diatas, atau saya tulis lagi seperti ini:

Tanya: DO/DOES + S + V1

Sama saja pasangannya. Untuk I, WE, YOU, THEY gunakan DO. Untuk SHE, HE, IT, Mufli, Ellen gunakan DOES. Contohnya begini:

Kalimat positifnya: I drink coffee
Kalimat tanya menjadi: DO you drink cofee?

Kalimat positif: She drinks coffe
Kalimat tanya: DOES She drink coffee?

Kalimat tanya seperti diatas disebut juga YES/NO Question. Karena jawabannya memang Yes atau No. Do You drink coffee? “Yes I do” jawabnya. Atau bisa bisa dijawab dengan lengkap: “Yes, I do drink coffee”. Dihilangkan DO nya juga boleh, menjadi kalimat positif lagi: “Yes I drink coffee”.

Ya, memang benar kalau Present Tense ini lebih rumit dibandingkan dengan Present Continuous Tense karena tiba-tiba kok pake DO, eh untuk orang ketiga tunggal pakai DOES segala, hehe.. Kalau dalam Present Continuous Tense nanti tinggal dibalik doang.

Determiners

Articles, Determiners,
and Quantifiers

Definition

Articles, determiners, and quantifiers are those little words that precede and modify nouns:

the teacher, a college, a bit of honey, that person, those people, whatever purpose, either way, your choice

Sometimes these words will tell the reader or listener whether we're referring to a specific or general thing (the garage out back; A horse! A horse! My kingdom for a horse!); sometimes they tell how much or how many (lots of trees, several books, a great deal of confusion). The choice of the proper article or determiner to precede a noun or noun phrase is usually not a problem for writers who have grown up speaking English, nor is it a serious problem for non-native writers whose first language is a romance language such as Spanish. For other writers, though, this can be a considerable obstacle on the way to their mastery of English. In fact, some students from eastern European countries — where their native language has either no articles or an altogether different system of choosing articles and determiners — find that these "little words" can create problems long after every other aspect of English has been mastered.

Determiners are said to "mark" nouns. That is to say, you know a determiner will be followed by a noun. Some categories of determiners are limited (there are only three articles, a handful of possessive pronouns, etc.), but the possessive nouns are as limitless as nouns themselves. This limited nature of most determiner categories, however, explains why determiners are grouped apart from adjectives even though both serve a modifying function. We can imagine that the language will never tire of inventing new adjectives; the determiners (except for those possessive nouns), on the other hand, are well established, and this class of words is not going to grow in number. These categories of determiners are as follows: the articles (an, a, the — see below; possessive nouns (Joe's, the priest's, my mother's); possessive pronouns, (his, your, their, whose, etc.); numbers (one, two, etc.); indefinite pronouns (few, more, each, every, either, all, both, some, any, etc.); and demonstrative pronouns. The demonstratives (this, that, these, those, such) are discussed in the section on Demonstrative Pronouns. Notice that the possessive nouns differ from the other determiners in that they, themselves, are often accompanied by other determiners: "my mother's rug," "the priests's collar," "a dog's life."

This categorization of determiners is based on Understanding English Grammar by Martha Kolln. 4rth Edition. MacMillan Publishing Company: New York. 1994.

Some Notes on Quantifiers

Like articles, quantifiers are words that precede and modify nouns. They tell us how many or how much. Selecting the correct quantifier depends on your understanding the distinction between Count and Non-Count Nouns. For our purposes, we will choose the count noun trees and the non-count noun dancing:

The following quantifiers will work with count nouns:
many trees
a few trees
few trees
several trees
a couple of trees
none of the trees

The following quantifiers will work with non-count nouns:
not much dancing
a little dancing
little dancing
a bit of dancing
a good deal of dancing
a great deal of dancing
no dancing

The following quantifiers will work with both count and non-count nouns:
all of the trees/dancing
some trees/dancing
most of the trees/dancing
enough trees/dancing
a lot of trees/dancing
lots of trees/dancing
plenty of trees/dancing
a lack of trees/dancing

In formal academic writing, it is usually better to use many and much rather than phrases such as a lot of, lots of and plenty of.

There is an important difference between "a little" and "little" (used with non-count words) and between "a few" and "few" (used with count words). If I say that Tashonda has a little experience in management that means that although Tashonda is no great expert she does have some experience and that experience might well be enough for our purposes. If I say that Tashonda has little experience in management that means that she doesn't have enough experience. If I say that Charlie owns a few books on Latin American literature that means that he has some some books — not a lot of books, but probably enough for our purposes. If I say that Charlie owns few books on Latin American literature, that means he doesn't have enough for our purposes and we'd better go to the library.

Unless it is combined with of, the quantifier "much" is reserved for questions and negative statements:

• Much of the snow has already melted.
• How much snow fell yesterday?
• Not much.

Note that the quantifier "most of the" must include the definite article the when it modifies a specific noun, whether it's a count or a non-count noun: "most of the instructors at this college have a doctorate"; "most of the water has evaporated." With a general plural noun, however (when you are not referring to a specific entity), the "of the" is dropped:

• Most colleges have their own admissions policy.
• Most students apply to several colleges.

An indefinite article is sometimes used in conjunction with the quantifier many, thus joining a plural quantifier with a singular noun (which then takes a singular verb):

• Many a young man has fallen in love with her golden hair.
• Many an apple has fallen by October.

	Countable Nouns	Uncountable Nouns	-
much		x	I don't have much money.
many	x	-	I don't have many apples.
few*	x	-	We know few people in the area. I would like to get to know more.
a few**	x	-	We know a few people in the area. I know enough people to keep me happy.
little*	-	x	I know little English. I am going to have a problem getting around England.
a little**	-	x	I know a little English, at least enough to get England.
enough	x	x	I have enough money.
plenty	x	x	I have plenty of money.

** a few/a little - means that there are not a lot of something, but there is enough.

• There are a few apples. There are enough apples.
• There are a people at the meeting. There are enough people to hold a meeting. There are not a lot people, at the meeting, but there are enough
• I know a little English. He know enough English to manage.
• I have a little money.

*few/little - means that is not enough of something.

• There are few apples. There are not enough apples.
• There are few people. There are not enough people at the meeting. We can't hold a meeting, because there are not enough people.
• There is little money. We can't buy a lot of expensive food.
• If things for the holiday. I don't have enough money, then we will stay home and have a great time.
• They know little English. They can't get around very well. They don't know enough English to manage.

A / An / The

Using Articles

What is an article? Basically, an article is an adjective. Like adjectives, articles modify nouns. English has two articles: the and a/an. The is used to refer to specific or particular nouns; a/an is used to modify non-specific or non-particular nouns. We call the the definite article and a/an the indefinite article.

the = definite article

a/an = indefinite article

For example, if I say, "Let's read the book," I mean a specific book. If I say, "Let's read a book," I mean any book rather than a specific book. Here's another way to explain it: The is used to refer to a specific or particular member of a group. For example, "I just saw the most popular movie of the year." There are many movies, but only one particular movie is the most popular. Therefore, we use the. "A/an" is used to refer to a non-specific or non-particular member of the group. For example, "I would like to go see a movie." Here, we're not talking about a specific movie. We're talking about any movie. There are many movies, and I want to see any movie. I don't have a specific one in mind. Let's look at each kind of article a little more closely.

Indefinite Articles: a and an

"A" and "an" signal that the noun modified is indefinite, referring to any member of a group. For example:

• "My daughter really wants a dog for Christmas." This refers to any dog. We don't know which dog because we haven't found the dog yet.
• "Somebody call a policeman!" This refers to any policeman. We don't need a specific policeman; we need any policeman who is available.
• "When I was at the zoo, I saw an elephant!" Here, we're talking about a single, non-specific thing, in this case an elephant. There are probably several elephants at the zoo, but there's only one we're talking about here.

Remember, using a or an depends on the sound that begins the next word. So...

• a + singular noun beginning with a consonant: a boy; a car; a bike; a zoo; a dog
• an + singular noun beginning with a vowel: an elephant; an egg; an apple; an idiot; an orphan
• a + singular noun beginning with a consonant sound: a user (sounds like 'yoo-zer,' i.e. begins with a consonant 'y' sound, so 'a' is used); a university; a unicycle
• In some cases where "h" is pronounced, such as "historical," us an:

An historical event is worth recording.

In writing, "a historical event" is more commonly used.

Remember that this rule also applies when you use acronyms:

Introductory Composition at Purdue (ICaP) handles first-year writing at the University. Therefore, an ICaP memo generally discusses issues concerning English 106 instructors. Another case where this rule applies is when acronyms start with consonant letters but have vowel sounds:

An MSDS (material safety data sheet) was used to record the data. An SPCC plan (Spill Prevention Control and Countermeasures plan) will help us prepare for the worst. If the noun is modified by an adjective, the choice between a and an depends on the initial sound of the adjective that immediately follows the article:

• a broken egg
• an unusual problem
• a European country (sounds like 'yer-o-pi-an,' i.e. begins with consonant 'y' sound)

Remember, too, that in English, the indefinite articles are used to indicate membership in a group:

• I am a teacher. (I am a member of a large group known as teachers.)
• Brian is an Irishman. (Brian is a member of the people known as Irish.)
• Seiko is a practicing Buddhist. (Seiko is a member of the group of people known as Buddhists.)

Definite Article: the

The definite article is used before singular and plural nouns when the noun is specific or particular. The signals that the noun is definite, that it refers to a particular member of a group. For example:

"The dog that bit me ran away." Here, we're talking about a specific dog, the dog that bit me.

"I was happy to see the policeman who saved my cat!" Here, we're talking about a particular policeman. Even if we don't know the policeman's name, it's still a particular policeman because it is the one who saved the cat.

"I saw the elephant at the zoo." Here, we're talking about a specific noun. Probably there is only one elephant at the zoo.

Count and Noncount Nouns

The can be used with noncount nouns, or the article can be omitted entirely.

• "I love to sail over the water" (some specific body of water) or "I love to sail over water" (any water).
• "He spilled the milk all over the floor" (some specific milk, perhaps the milk you bought earlier that day) or "He spilled milk all over the floor" (any milk).

"A/an" can be used only with count nouns.

• "I need a bottle of water."
• "I need a new glass of milk."

Most of the time, you can't say, "She wants a water," unless you're implying, say, a bottle of water.

Geographical use of the

There are some specific rules for using the with geographical nouns. Do not use the before:

• names of most countries/territories: Italy, Mexico, Bolivia; however, the Netherlands, the Dominican Republic, the Philippines, the United States
• names of cities, towns, or states: Seoul, Manitoba, Miami
• names of streets: Washington Blvd., Main St.
• names of lakes and bays: Lake Titicaca, Lake Erie except with a group of lakes like the Great Lakes
• names of mountains: Mount Everest, Mount Fuji except with ranges of mountains like the Andes or the Rockies or unusual names like the Matterhorn
• names of continents (Asia, Europe)
• names of islands (Easter Island, Maui, Key West) except with island chains like the Aleutians, the Hebrides, or the Canary Islands

Do use the before:

• names of rivers, oceans and seas: the Nile, the Pacific
• points on the globe: the Equator, the North Pole
• geographical areas: the Middle East, the West
• deserts, forests, gulfs, and peninsulas: the Sahara, the Persian Gulf, the Black Forest, the Iberian Peninsula

Omission of Articles

Some common types of nouns that don't take an article are:

• Names of languages and nationalities: Chinese, English, Spanish, Russian
• Names of sports: volleyball, hockey, baseball
• Names of academic subjects: mathematics, biology, history, computer science

Present Perfect - Simple Past

Present Perfect

[has/have + past participle]

1. Present perfect - form
The present perfect of any verb is composed of two elements : the appropriate form of the auxiliary verb to have (present tense), plus the past participle of the main verb. The past participle of a regular verb is base+ed, e.g. played, arrived, looked. For irregular verbs, see the Table of irregular verbs in the section called 'Verbs'.

Affirmative
Subject		to have	past participle
She		has	visited
Negative
Subject		to have + not	past participle
She		hasn't	visited
Interrogative
to have		subject	past participle
Has		she	visited..?
Interrogative negative
to have + not		subject	past participle
Hasn't		she	visited...?

Example: to walk, present perfect

Affirmative	Negative	Interrogative
I have walked	I haven't walked	Have I walked?
You have walked	You haven't walked	Have you walked?
He, she, it has walked	He, she, it hasn't walked	Has he,she,it walked
We have walked	We haven't walked	Have we walked?
You have walked	You haven't walked	Have you walked?
They have walked	They haven't walked	Have they walked?

2. Present perfect, function
The Present Perfect is used to indicate a link between the present and the past. The time of the action is before now but not specified, and we are often more interested in the result than in the action itself.

BE CAREFUL! There may be a verb tense in your language with a similar form, but the meaning is probably NOT the same.

The present perfect is used to describe:

1.An action or situation that started in the past and continues in the present. Example: I have lived in Bristol since 1984 (= and I still do.)

2. An action performed during a period that has not yet finished. Example: She has been to the cinema twice this week (= and the week isn't over yet.)

3. A repeated action in an unspecified period between the past and now. Example: We have visited Portugal several times.

4. An action that was completed in the very recent past, (expressed by 'just'). Example: I have just finished my work.

5. An action when the time is not important. Example: He has read 'War and Peace'. (the result of his reading is important)

Note: When we want to give or ask details about when, where, who, we use the simple past. Example: He read 'War and Peace' last week.

Examples:

1. Actions started in the past and continuing in the present.
a. They haven't lived here for years.
b. She has worked in the bank for five years.
c. We have had the same car for ten years.
d. Have you played the piano since you were a child?

2. When the time period referred to has not finished.
a. I have worked hard this week.
b. It has rained a lot this year.
c. We haven't seen her today.

3. Actions repeated in an unspecified period between the past and now.
a. They have seen that film six times.
b. It has happened several times already.
c. She has visited them frequently.
d. We have eaten at that restaurant many times.

4. Actions completed in the very recent past (+just).
a. Have you just finished work?
b. I have just eaten.
c. We have just seen her.
d. Has he just left?

5. When the precise time of the action is not important or not known.
a. Someone has eaten my soup!
b. Have you seen 'Gone with the Wind'?
c. She's studied Japanese, Russian and English.

SIMPLE PAST

BE CAREFUL! The simple past in English may look like a tense in your own language, but the meaning may be different.

1. Simple past, form

Regular verbs: base+ed
e.g. walked, showed, watched, played, smiled, stopped

Irregular verbs: see list in verbs

Simple past, be, have, do:

Subject	Verb
	Be	Have	Do
I	was	had	did
You	were	had	did
He, she, it	was	had	did
We	were	had	did
You	were	had	did
They	were	had	did

Affirmative
a. I was in Japan last year
b. She had a headache yesterday.
c. We did our homework last night.

Negative and interrogative
Note: For the negative and interrogative simple past form of "do" as an ordinary verb, use the auxiliary "do", e.g. We didn't do our homework last night. The negative of "have" in the simple past is usually formed using the auxiliary "do", but sometimes by simply adding not or the contraction "n't".
The interrogative form of "have" in the simple past normally uses the auxiliary "do".

• They weren't in Rio last summer.
• We hadn't any money.
  
• We didn't have time to visit the Eiffel Tower.
  
• We didn't do our exercises this morning.
  
• Were they in Iceland last January?
  
• Did you have a bicycle when you were a boy?
  
• Did you do much climbing in Switzerland?

Simple past, regular verbs

Affirmative
Subject	verb + ed
I	washed
Negative
Subject	did not	infinitive without to
They	didn't	visit ...
Interrogative
Did	subject	infinitive without to
Did	she	arrive...?
Interrogative negative
Did not	subject	infinitive without to
Didn't	you	like..?

Example: to walk, simple past.

Affirmative	Negative	Interrogative
I walked	I didn't walk	Did I walk?
You walked	You didn't walk	Did you walk?
He,she,it walked	He didn't walk	Did he walk?
We walked	We didn't walk	Did we walk?
You walked	You didn't walk	Did you walk?
They walked	They didn't walk	Did they walk?

Note: For the negative and interrogative form of all verbs in the simple past, always use the auxiliary 'did''.

Examples: Simple past, irregular verbs

to go
a. He went to a club last night.
b. Did he go to the cinema last night?
c. He didn't go to bed early last night.

to give
d. We gave her a doll for her birthday.
e. They didn't give John their new address.
f. Did Barry give you my passport?

to come
g. My parents came to visit me last July.
h. We didn't come because it was raining.
i. Did he come to your party last week?

2. Simple past, function

The simple past is used to talk about a completed action in a time before now. Duration is not important. The time of the action can be in the recent past or the distant past.

• John Cabot sailed to America in 1498.
• My father died last year.
• He lived in Fiji in 1976.
• We crossed the Channel yesterday.

You always use the simple past when you say when something happened, so it is associated with certain past time expressions

Examples:

• frequency:
  often, sometimes, always;
• a definite point in time:
  last week, when I was a child, yesterday, six weeks ago.
• an indefinite point in time:
  the other day, ages ago, a long time ago etc.

Note: the word ago is a useful way of expressing the distance into the past. It is placed after the period of time e.g. a week ago, three years ago, a minute ago.

Examples:

a. Yesterday, I arrived in Geneva.
b. She finished her work at seven o'clock.
c. We saw a good film last week.
d. I went to the theatre last night.
e. She played the piano when she was a child.
f. He sent me a letter six months ago.
g. Peter left five minutes ago.