Present perfect or past simple?

A I have done it or I did

Sports Commentator: And that's all Manchester has...

Manchester fan: Yes, yes! We've won the cup, It's ours at last!

Chelsea fan: Well, we won the cup last year.

The present perfect tells us about the past and the present. United have won the Cup, so it's theirs now.

The past simple tells us about the past, a time which is finished. Last year is in the past.

We use the past simple (not the present perfect) to talk about times in the past such as yesterday, last week, in 1994, a hundred years ago.

We watched United last week. NOT We have watched United last week.

Long ago dinosaurs lived here. NOT Long ago dinosaurs have lived here.

Here are some more examples.

PRESENT PERFECT

Emma has packed her case. (So her things are in the case now.)

Mike has repaired the chair. (So it's all right now.)

The plane has just landed. I've turned the heating on. (It's on now.)

I've dropped my calculator. (It's on the floor now.)

PAST SIMPLE

Emma packed her case last night. (Her things may be unpacked now.)

Mike repaired the chair. (It may be broken again now.)

The plane landed ten minutes ago.

I turned the heating on earlier, but it's off again now.

I dropped my calculator, but it seems to be OK.

B I've done it. I did it yesterday.

Trevor: We've bought a new car.

Tom: Oh, have you? What sort?

Laura: An Adagio. We bought it last week.

We often give a piece of news in the present perfect, e.g. We've bought a new car. (The car is ours now.) We use the past simple, e.g. We bought it last week, to give details or to ask for details about things such as when and where it happened.

Here are some more examples.

I've found my wallet. ~ Oh, good. Where did you find it?

Your parcel has arrived. The postman brought it at eight o'clock.

They've closed the factory. ~ Really? When did they do that?

C Structures with for, since and last

PRESENT PERFECT

We can say that something hasn't happened for a long time or since a specific time in the past.

We haven't had a party for ages. We haven't had a party since Christmas.

PAST SIMPLE

We can say that it is a long time since something happened or when was the last time it happened.

It's ages since we last had a party. Christmas was the last time we had a party.

D I have been or I was

PRESENT PERFECT

We use the present perfect for a state which has gone on up to the present.

We've lived here for ten years. (And we still live here.)

PAST SIMPLE

We use the past simple for a state in the past, in a period which is finished.

We lived there for ten years. (We don't live there now.)

E Have you (ever)...? and Did you (ever)...?

PRESENT PERFECT

We use the present perfect for actions in a period of time up to the present.

This young director has made four films so far. He has made films means that it is possible he will make more films.

Here are some more examples.

Have you ever been to America? ~ Yes, twice.

I've played table tennis before.

We've never had any money.

PAST SIMPLE

We use the past simple for actions in the past, a period which is finished.

The director made many films in his long career. He made films means that his career in films is over. He won't make any more.

Did Churchill ever go to America? ~ Yes, I think so.

I played table tennis at college.

We never had any money in those days.

F Today, this week, etc

PRESENT PERFECT

We use today and phrases with this for a period up to the present.

It hasn't rained today.

Have you seen this week's magazine?

PAST SIMPLE

We use yesterday and phrases with last for a past period.

It rained yesterday.

Did you see last week's magazine?

But sometimes today etc can mean a past period. Compare:

I haven't seen Rachel today. I didn't see Sarah at work today.

(It's still daytime.) (The working day is over.)

Has the post come this morning? Did the post come this morning?

(It's still morning.) (It's later in the day.)