We use perfect aspect to look back from a specific time and talk about things up to that time or about things that are important at that time.
We use the present perfect to look back from the present:
I have always enjoyed working in Italy. [and I still do]
She has left home, so she cannot answer the phone.
We use the past perfect to look back from a time in the past:
It was 2006. I had enjoyed working in Italy for the past five years.
She had left home, so she could not answer the phone.
We use will with the perfect to look back from a time in the future:
By next year I will have worked in Italy for 15 years.
She will have left home by 8.30, so she will not be able to answer the phone.
We use the present perfect:
- for something that started in the past and continues in the present:
They've been married for nearly 50 years.
She has lived in Liverpool all her life.
- when we are talking about our experience up to the present:
I've seen that film before.
I've played the guitar ever since I was a teenager.
He has written three books and he is working on another one.
- for something that happened in the past but is important in the present:
I can't get in the house. I've lost my keys.
Teresa isn't at home. I think she has gone shopping.
We normally use the present perfect continuous to emphasise that something is still continuing in the present:
It's been raining for hours.
I'm tired out. I've been working all day.
We use the past perfect:
- for something that started in the past and continued up to a later time in the past:
When George died, he and Anne had been married for nearly 50 years.
She didn't want to move. She had lived in Liverpool all her life.
- when we are reporting our experience up to a point in the past:
My eighteenth birthday was the worst day I had ever had.
I was pleased to meet George. I hadn't met him before, even though I had met his wife several times.
- for something that happened in the past and is important at a later time in the past:
I couldn't get into the house. I had lost my keys.
Teresa wasn't at home. She had gone shopping.
We use the past perfect continuous to show that something started in the past and continued up to a time in the past or was important at that time in the past:
Everything was wet. It had been raining for hours.
He was a wonderful guitarist. He had been playing ever since he was a teenager.
Modals with the perfect
We use will with the perfect to show that something will be complete at or before some time in the future:
In a few years they will have discovered a cure for the common cold.
I can come out tonight. I'll have finished my homework by then.
We use would with the perfect to refer to something that did not happen in the past:
If you had asked me, I would have helped you.
I would have helped you, but you didn't ask me.
You didn't ask me or I would have helped you.
We use other modals with the perfect when we are looking back from a point in time. The point of time may be in the future:
We'll meet again next week. We might have finished the work by then.
I will phone at six o'clock. He should have got home by then.
or the present:
It's getting late. They should have arrived by now.
He's still not here. He must have missed his train.
or the past:
I wasn't feeling well. I must have eaten something bad.
I checked my mobile phone. She could have left a message.
- Perfect aspect 1
- Perfect aspect 2
- Perfect aspect 3