Present perfect 现在完成时

I’ve just …  I’ve already …  I haven’t … yet

I’ve just …

just = a short time ago

A: Axe Diane and Paul here?
B: Yes, they‘ve just arrived.

A: Are you hungry?
B: No, I‘ve just had dinner.

D A: Is Tom here?
B: No, I’m afraid he‘s just gone.

I’ve already …

already = before you expected / before I expected

A: What time are Diane and Paul coming?
B: They’ve already arrived.
(= before you expected)

It’s only 9 o’ clock and Anna has already gone to bed. (= before I expected)

A: Jon, this is Emma.
B: Yes, I know. We‘ve already met.

I haven’t … yet / Have you … yet?

yet = untill now
Used in negative sentences and questions. Yet is useally at the end.

yet in negative sentences (I haven’t … yet)

A: Are Diane and Paul here?
B: No, they haven’t arrived yet.
(but B expects Diane and Paul to arrive soon)

A: Does James know that you’re going away?
B: No, I haven’t told him yet.
(but B is going to tell him soon)

Silvia has bought a new dress, but she hasn’t worn it yet.

yet in questions (Have you … yet?)

A:Have Diane and Paul arrived yet?
B: No, not yet. We’re still waiting for them.

A: Has Nicole started her new job yet?
B: No, she starts next week.

A: This is my new dress.
B: Oh, it’s nice. Have you worn it yet?

Have you erver … ?

We use the present perfect (have been/ have had/ have played etc. ) when we talk about a time from the past until now – for example, a person’s life:

‘Have you been to France?’ ‘No, I haven’t.’
I‘ve been to Canada, but I haven’t been to the United States.
Mary is an interesting person. She has had many different jobs and has lived in many places.
I‘ve seen that woman before, but I can’t remember where.
How many times has Brazil won the World Cup?
‘Have you read this book?’ ‘Yes, I‘ve read it twice.’ 

present perfect + ever (in questions) and never:

‘Has Ann ever been to Australia?’ ‘Yes, once.’
‘Have you ever played golf?’ ‘Yes, I play a Jot.’
My siter has never travelled by plane.
I‘ve never ridden a horse.
‘Who is that man?’ ‘I don’t know. I‘ve never seen him before.’

gone and been

Bill has gone to Spain. (= he is in Spain now)
Bill has been to Spain. (= he went to Spain, but now he is back)

Compare

I can’t find Susan. Where has she gone? (= where is she now?)
Oh, hello Susan! I was looking for you. Where have you been?

How long have you … ?

have been / have had / have lived / have know etc.

– How long have Dan and Kate been married?  – They have been married for five years.
– How long have you known her?  – I‘ve known her for a long time.
– How long has she lived in London? – She has lived there all her life.
– How long have you had your car? – I‘ve had it since April.

Present perfect continuous

have/has been + doing

How long have you been learning German?
I’ve been learning German for two years.
How long has he been watching TV?
He’s been watchingTV since 5 o’clock. It’s been raining all day.