Present perfect (I have done) (1) в английском языке

Study this example situation:

Tom is looking for his key. He can't find it.
He has lost his key.

"He has lost his key" means that he lost it a short time ago and he still doesn't have it.

This is the present perfect (simple) tense:

I/we/they/you have (= I've, etc.)
he/she has(= he's, etc.)
I (etc.) haven't
he/she hasn't
has he/she
have you (etc.)

We form the present perfect with have/has + the past participle. The past participle often ends in -ed (opened, decided), but many important verbs are irregular (lost, written, done, etc.).
For a list of irregular verbs see this.

When we use the present perfect, there is a connection with the present:

  • I've lost my key. ( = I don't have it now.)

  • Jim has gone to Canada. ( = He is in Canada or on his way there now.)

We often use the present perfect to give new information or to announce a recent happening:

  • I've lost my key. Can you help me look for it?

  • Did you hear about Jim? He's gone to Canada.

You can use the present perfcct with just (= a short time ago):

  • "Would you like something to eat?" "No, thanks. I've just had lunch."

  • Hello, have you just arrived?

Use the present perfect with already to say something has happened sooner than expected:

  • "Don't forget to mail the letter." "I've already mailed it."

  • "When is Tom going to start his new job?" "He has already started."

Note that you can also use the simple past (I did /I lost, etc.) in the above situations.

  • I lost my key. Can you help me look for it?

  • "Would you like something to cat?" "No thanks. I just had lunch."

  • "Don't forget to mail the letter." "I already mailed it."

Study the difference between gone to and been to:

  • Beth is on vacation. She has gone to Italy. ( = She is there now or she is on her way there.)

  • Tom is back from his vacation. He has been to Italy. ( = He was there, but now he has come back.)