When to use "have"

[Ciao2828]

Would someone write:

I won the race.
or
I have won the race.

I faxed the papers.
or
I have faxed the papers.

Can someone tell me the difference??

Thanks,

Ciao2828

[Conchita]

I won the race/I faxed the papers yesterday. => Past simple if we say when it happened.

I have won the race/I have faxed the papers. => Present perfect if we don't say when.

Oh, and welcome to the forum, Ciao!

[Yankee]

Hi ciao2828

The sentences you posted are very simple ones. All of them are grammatical, so you can write any of them. Without more context, however, it's impossible to say that one sentence would be "better" than the other.

If you've got time to do a bit of reading, take a look at this thread:
Phrase 'the court has appointed me your public defender'

If you need more input about the difference between the simple past tense and the present perfect, why don't you first tell us a bit of what you already know about those two tenses.