Unit 25: PRESENT PERFECT -- USE
Both the simple and the continuous formation (Unit 24) mean, very generally, 'past time and present time together'.
Continuation up to the present time
I've lived here all my life.
= I was born here, I live here now.
He has been working there for five years now.
= He started here five years ago and he works there now.
How long have you known John?
= When did you first meet?
We haven't seen each other since last January.
= Last January was the last time we saw each other.
A past event which is important for now
Look! The sun has come out.
So now the weather is fine.
Look! It's been snowing.
So now the ground is white.
Have you seen John?
I want to speak to him.
Help! Somebody has taken my wallet.
General experiences in life (simple formation only)
It's the biggest set of tires I've ever seen in my entire life.
They've been on this truck for six months.
Have you ever driven truck?
Simple and continuous formationThe meanings of the simple and continuous formations are basically the same but sometimes they are a little different.
They have built a new work camp.
Now it is finished.
They've been building a new work camp.
It is probably not finished.
NOTICE: Have got is grammatically present perfect but it usually has a present simple meaning (Unit 20):
Have you got a brother called John?
= Do you have . . . ?
I've got a terrible headache.