Use the present perfect tense when :
> Something happened in the past, and
> The result of happening is still there.

Example :
1. I have closed the door
(The result : The door is still close)
2. Ayu has gone to Japan.
(The result : Ayu is still in Japan)


This is different from the simple past tense :
1. I closed the door
(The result : Ypu don't know if the door still closed or not)
2. Ayu went ti Japan
(The result : She is no longer in Japan)

*The Affirmative form
Pattern : S + Auxiliary Verb (Have/Has) + past participle + ....
Example :
1. He has bought a car here (He has the car)
2. I lived in Japan (I know Japan)

This tense often uses "for" and "since" especially to express the continuing events (peristiwa yang masih berlanjut)
Example :
1. I have been here for 15 minutes
2. I have been here since 9 O'clock

Contraction of 's may be confusing sometimes.
It can come from verb be (is) or the auxilliary has. But you can understand it from the context. The key are :
>The contraction of 's from the auxulliary verb has when it is followed by past particple.
>The contraction of 's from the verb be (is) when it is followed by nouns, adjective, or V-ing.

Example :
1.She's borrowed my book.
(Auxulliary has)
2.She's listening to music.
(verb be)


*The negative form
Pattern : S + Auxilliary Verb (Have/has) + not + Past Participle + ....
Example :
1.Susi has not gone to the movie.
2.He has not finished repairing the radio.

*The interrogative form
Pattern : Auxilliary (Have/has) + S + Past Participle + ... + ?
Example :
1.Has Nina finisher his homework ?
2.Have students done their assignments ?

The present perfect tense often uses adverb "just, ever, never, and already", especially to express the speaker's experiences or new information.
(Note : never = not ever)

Example :
(+) We have just lived in Japan
( -) We have not just lived in Japan
(?) Have we just lived in Japan ?

PAST PERFECT TENSE

Past perfect tense is a kind of tense that is used to describe an Action or an event that started in a certain time in the past and completed of finished certain time in the past too; or past perfect tense is used to Express an Action or an event that had happened before that other event or action happened.

Formula of Verbal Sentence
+ SUBJECT + HAD + V3
- SUBJECT + HAD + NOT + V3
? HAD + SUBJECT + V3?

Example:
+ She had slept when I came last night.
- She had not slept when I came last night.
? Had she slept when I came last night?

Formula of Nominal Sentence
+ SUBJECT + HAD + BEEN+ NON VERB
- SUBJECT + HAD +NOT + BEEN+ NON VERB
? HAD + SUBJECT + BEEN+ NON VERB?

Example:
+ I had been there when the accident hapenned.
- I had not been Three when the accident hapenned.
? Had had been there when the accident hapenned?

I had = I’d
You had = You’d
We had = We’d
They had = they’d
He had = he’d
She had = She’d
It had = It’d