UNIT 9. 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 / 10 minutes ago / in 1999 / when I was a child). Use a past tense:

It was very cold yesterday. (not has been)
Paul and Lucy went out 10 minutes ago. (not have gone)
Did you eat a lot of candy when you were a child? (not have you eaten)
I got home late last night. I was very tired and went straight to bed.

Use the simple past to ask. When …? or What time …? :

When did you friends. get here? (not have … gotten)
What time did you finished work?

Compare:

Present Perfect or Simple Past

Tom has lost his key. He can’t get into the house. (or Tom lost…)
Is Carla here or has she left? (or Did she leave?)

Simple Past Only

Tom lost his key yesterday. He couldn’t get into the house.
When did Carla leave?

B

Compare:

Present Perfect (have done)

I’ve done a lot of work today.

We use the present perfect for a period of time that continues until now. For example: today / this week / since 1999.

     unfinished
     +---------+
     |  today  |
-----+---------+---------------------------
past      now

It hasn’t rained this week.
Have you seen Lisa this morning? (It is still morning)
Have you seen Tim recently?
I don’t know where Lisa is. I haven’t seen her. (= I haven’t seen her recently)
We’ve been waiting for an hor. (We are still waiting now)
John lives in Los Angels. He has lived there for seven years.
I have never played golf. (in my life)
It’s the last day of your vacation. You sai : It’s been a really good vacation.
I’ve really enjoyed it.

Simple Past(did)

I did a lot of work yesterday.

We use the simple past for a finished time in the past. For example: yesterday / last week / from 1999 to 2005.

         finished          |
     +-------------+       |
     |  yesterday  |       |
-----+-------------+-------+-------------------
past                   now

It didn’t rain last week.
Did you see Lisa this morning? (It is now afternoon or evening)
Did you see Tim on Sunday?
A:Was Lisa 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)
John lived in New York for 10 years.
Now he lives in Los Angels.
I didn’t play golf last summer.
After you come back from vacation, you say: It was a really good vacation. I really enjoyed it.