Let'study about Tenses

1. Present Time

The simple present expreses daily habits or usual activities.

• ann takes a bath everyday
• i usually eat lunch at a cafetaria

The simple present expreses general statement of fact.

• Babies cry
• The Earth revolves arround the sun
• A square has four equal sides
• The sky is blue

conclusion: The simple present is used for events or situations that exits always, usually, or habitually in the past, present, and future.
The forms :
statement : {i-you-we-they} work {he-she-it}works
negative : {i-you-we-they}do not work {he-she-it} does not work
question : do {i-you-we-they{ work ? does {he-she-it} work ?


2. Present progressive(continous)
The present progressive expresses an activity that is in progres(is occuring, is happening) right now.The event is in progress at the time the speaker is saying the sentence.The event began in the past, in in progress now, and willprobably continue in the future.

• ann can't answer the phone right now,because she's taking a shower
• it'noon.i'm eating lunch now
• jimmy and susi are babies.They are crying.Maybe they are hungry

The Form:
i am working
{you-we-yhey} are working
{he-she-it} is working

3. Past Time
The simple past is used to talk about activity or situatuons that began and ended in the past.
eg,yesterday,last night,two days ago,in 1990.

• mary walked down town yesterday
• i slept for eight hours last night
• bob stayed home yesterday morning

The form:
statement : s + v2
negative : s + didn't+ v1
question : did + s + v1

4. Future Time
Future time is used to express future time. By using Will ang Be Going To.

• I am going to visit you tomorrow
  
• I will visit you tomorrow
  
• I am going to be there tomorrow afternoon
• I will be there tomorrow morning
  

All of these examples have the same meaning.

• I shall cook tomorrow morning
• We shall cook tomorrow morning

The use of shall with i or we to express future time is infrequent and formal.
Will and Be going to usually give the same meaning, but sometimes they express the different meaning.

A. Will
(+) s + will + verb 1 + complement
ex : he will bring my book tonight
(-) s + will + not (won't) + s + verb 1 + complement
ex : she won't go to school tomorrow
(?) will + s + verb 1 + complement ?
ex : will you come to my house tomorrow ?
(contractions) : I'll, You'll, he'll, she'll, we'll, they'll, it'll. Bob'll. teacher'll.
Will is usually contracted with pronouns in both speech and informal writing
Will is also usually contracted with nouns in speech, but usually not in writing

B. Be Going TO vs Will
Be going to and will are the same when they are used to make prediction about the future.

• ex: she's going to succed because she work hard

she will succeed because she works hard
These example have the same meaning.

Be Going To is used to express something have planned before.
ex : i bought a laptop, i am going to type a novel.
(+) s + Be going to + verb 1 + complement
(-) s + Be + not + going to + verb 1 + cpmplement
(?) Be + s + Going to + verb 1 + complement

Will is used to express willingness. it means that the speaker says it spontantly at the time of speaking without any planning before.
ex: don't worry i will lend you my money.

5. Present Perfect
The present perfect expresses activities or situation occured or did not occur before now or at the unspecified time.
(+) i, you, we, they + have + verb 3 + complement
ex: i have eaten lunch
she, he, it + has + verb 3 + complement
ex: he has gone to paris
(-) i, you, we, they + haven't + verb 3 + complement
ex: we haven't done our homework
she, he, it + hasn't + verb 3 + complement
ex: she hasn't washed her clothes
(?) have + i, you, we, they + verb 3 + complement
ex: have they prefered they presentation?
has + she, he, it + verb 3 + complement
ex: has he arrived at school ?