Present Perfect Tense

The present perfect tense is formed of the present tense and perfect aspect. We use present perfect describe a past finished action that has present consequences.

The present perfect is formed of the present form of Have (have/has) + Past Participle.

I have finished my assignment.
He has written an essay.

FORM: [has/have + past participle]

Past Action with Present Result

1. We use present perfect for a past action that has present consequences. Note that the emphasis is more on the result than the action itself.

I have bought a home in London. 
He has passed MBBS. 

Just/ Already/ Lately/ Recently/ Ever/ Yet

2. We use present perfect with adverbs like just, lately, recently, ever, yet that indicate recent past. 

He has already finished his homework. 
They have just arrived here. 

Life Experience

3. We use present perfect to express life experience. We don't say when the experience happened, just sometime in the past. 

    I have gone to New York.
    She has lived in London.
    They have visited Florida three times.

4. If we mention the past time, we must use past simple, not the present perfect. 

I went to New York last year.
She lived in London then.
They visited Florida two months ago.

'Been' and 'Gone'

5. We use been and gone as the past participle of go. But there is a great difference between them. 

Been

6. We use been when someone has gone to a place and returned.

I have been to Dhaka.
She has been to school today. 

7. We use gone when someone has gone to a place and has not returned.

I have gone to Dhaka.
They have gone to Japan.  (now they're in Japan)

Unfinished Actions:

8. You know verbs of mental actions and stative verbs are not used in continuous. So, in place of present perfect continuous, we use present perfect with for and since to describe an unfinished action.

'Since' or 'For'? 

9. We use since + a point of time/fixed time (2014, May 1st, last year, 2pm) 

I have liked him since 2019. 
We have known each other since 1992.
She has been there since last night.

10. We use for + a period of time (2 hours, three years, six months)

I have liked him for all my life. 
We have known each other for ten years.
She has been there for five months.