Present Perfect Tensesule

PRESENT PERFECT
TENSE
The autumn has already arrived How do you know? LOOK AT THE EXAMPLES:
I

have seen that movie twenty times.  I think I have met him once before.
 There have been many earthquakes in California.
 We haven’t cleaned the house yet.
 Recently, we have argued a lot.
 Have you talked to him lately?
 I have already finished my homework. PRESENT PERFECT TENSE

FORM: have / has + past participle

Affirmative:

I have seen the film before.
She has seen the film before.

Interrogative: Have you seen the film before?
Has she seen the film before?
Negative:

They haven’t seen the film before.
He hasn’t seen the film before.

Present Perfect Tense
Uses of the present perfect 1Recent events: It is used to describe recent events without a definite time. The idea of time or place in the speaker’s mind makes the event recent. A time expression may emphasize recentness: just, recently, lately Why are they so happy?
They have just won a prize so they are really pleased PRESENT PERFECT TENSE
2- Personal experiences: It is used to express personal experiences, there is not a definite time given. The time expressions ever and never are very often used with this meaning

I have never been to
Japan. Have you ever been there?

PRESENT PERFECT TENSE
3- It is used to express actions that started in the past and continue to the present, the time period is not finished. We use for and since with this meaning. We use for with periods of time and since with points of time. I haven’t eaten since yesterday morning. I am really hungry
I haven’t drunk anything for two days. I am terribly thirsty NOTE THE DIFFERENCE
 He

has been to
London.  Now he is here. He can tell you wonderful stories about London.
 He has been in London for two weeks.  He is still in London.
 Where’s Peter? He has gone to London. 
He is in Italy or on his way to London.