UNIT 14. Present perfect and past (2) (I have done and I did)

A. Do not use the present perfect (I have done) when you talk about a finished time (for example, yesterday/ten minutes ago/in 1985/when I was a child). Use a past tense:

* The weather was nice yesterday. (not 'has been nice')

* They arrived ten minutes ago. (not 'have arrived')

* I ate a lot of sweets when I was a child. (not 'have eaten')

* A: Did you see the news on television last night? (not 'Have you seen')

B: No, I went to bed early. (not 'have gone')

Use a past tense to ask When ...? or What time ...?:

* When did they arrive? (not 'have they arrived')

* What time did you finish work?

Compare:

Present perfect

* Tom has lost his key. He can't get into the house.

Here, we are not thinking of the past action. We are thinking of the present result of the action: Tom doesn't have his key now.

Past simple

* Tom lost his key yesterday. He couldn't get into the house.

Here, we are thinking of the action in the past. We don't know from this sentence whether Tom has his key now.

B. Compare present perfect and past:

Present perfect (have done)

* I've done a lot of work today.

We use the present perfect for a period of time that continues from the past until now. For example, today, this week, since 1985.

* It hasn't rained this week.

* Have you seen Ann this morning? (it is still morning)

* Have you seen Ann recently?

* I don't know where Ann is. I haven't seen her. (= I haven't seen her recently)

* We've been waiting for an hour. (we are still waiting now)

* Ian lives in London. He has lived there for seven years.

* I have never played golf. (in my life)

The present perfect always has a connection with now. See Units 7-12.

Past simple (did)

* I did a lot of work yesterday.

We use the past simple for a finished time in the past. For example, yesterday, last week, from 1985 to 1991.

* It didn't rain last week.

* Did you see Ann this morning? (it is now afternoon or evening)

* Did you see Ann on Sunday?

* A: Was Ann at the party on Sunday?

B: I don't think so. I didn't see her.

* We waited (or were waiting) for an hour. (we are no longer waiting)

* Ian lived in Scotland for ten years.

Now he lives in London.

* I didn't play golf when I was on holiday last summer.



The past simple tells us only about the past. See Units 5-6.