The present perfect is formed from the present tense of the verb have and the past participle of a verb:
The present perfect continuous is formed with have/has been and the -ing form of the verb:
We use the present perfect tense:
for something that started in the past and continues in the present:
They’ve been married for nearly fifty years.
She has lived in Liverpool all her life.
Note: We normally use the present perfect continuous for this:
She has been living in Liverpool all her life.
It’s been raining for hours.
for something we have done several times in the past and continue to do:
I’ve played the guitar ever since I was a teenager.
He has written three books and he is working on another one.
I’ve been watching that programme every week.
We often use a clause with since to show when something started in the past:
They’ve been staying with us since last week.
I have worked here since I left school.
I’ve been watching that programme every week since it started.
when we are talking about our experience up to the present:
Note: We often use the adverb ever to talk about experience up to the present:
My last birthday was the worst day I have ever had.
Note: and we use never for the negative form:
Have you ever met George?
Yes, but I’ve never met his wife.
for something that happened in the past but is important at the time of speaking:
I can’t get in the house. I’ve lost my keys.
Teresa isn’t at home. I think she has gone shopping.
I’m tired out. I’ve been working all day.
We use the present perfect of be when someone has gone to a place and returned:
A: Where have you been?
B: I’ve just been out to the supermarket.
A: Have you ever been to San Francisco?
B: No, but I’ve been to Los Angeles.
But when someone has not returned we use have/has gone:
A: Where is Maria? I haven’t seen her for weeks.
B: She's gone to Paris for a week. She’ll be back tomorrow.
We often use the present perfect with time adverbials which refer to the recent past:
just; only just; recently;
Scientists have recently discovered a new breed of monkey.
We have just got back from our holidays.
or adverbials which include the present:
ever (in questions); so far; until now; up to now; yet (in questions and negatives)
Have you ever seen a ghost?
Where have you been up to now?
Have you finished your homework yet?
No, so far I’ve only done my history.
We do not use the present perfect with an adverbial which refers to past time which is finished:
I have seen that film
We have just bought a new car
last week. we have been to California.
When we were children
But we can use it to refer to a time which is not yet finished:
Have you seen Helen today?
We have bought a new car this week.