Here is an overview of the main functions of the perfect aspect.
We use the present perfect to show that something has continued up to the present time.
They've only been together for two years.
He has lived in Istanbul all his life.
Another function of the present perfect is to show that something that happened in the past is still important in the present.
I’ve forgotten my phone at home. I can't call Sarah.
John isn't at work. He's gone to Japan for two weeks.
We use the present perfect to refer to actions in the past that are relevant to the present but there can be no specific time reference in the sentence.
I've been to Germany. or I was in Germany last year. But NOT I have been to Germany last year.
We use the present perfect continuous to show that something has been continuing to the present:
I've been studying for three hours.
She has been working in tourism for a decade.
We use the past perfect to show that something continued up to a point in the past.
When I met Peter I had been in London for two weeks.
We also use the past perfect to show something was important at the time in the past.
I couldn't call Sarah because I had left my phone at home.
John wasn't at work. He'd gone to Japan.
We use the past perfect continuous to show that something had been continuing up to a time in the past or was important at that time.
We were all tired. We had been walking around the city all day.
John wasn't at work. I had been trying to reach him for hours.
We use the future perfect – will + have + past participle – to show that something will be complete at some time in the future.
Call me after five. I'll have finished studying by then.
The future perfect can be used with a past action.
When you arrive in Malta next week I'll have been here for a month.
Or a future action.
You're going to London in May. I'll have been there for two months by then.
It is important to know that most native speakers avoid overuse of the past and future perfect.
Lesson by Tristan, teacher at EC Malta English school
Now choose the correct form for the following: