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” = He lost it and he still hasn’t got it.
Have/ has lost is the Present Perfect Simple:
* I/ we/ they/ you have ( = I’ve/ we’ve etc.) finished /lost /done/ been etc.
* he/ she/ it has ( = he’s/ she’s etc.) finished /lost /done/ been etc.
The Present Perfect Simple is have/ has + past participle.
The past participle often ends in – ed (finished/ decided etc.), but many important verbs are irregular (lost/ done/ been/ written etc.).
When we use the Present Perfect there is always a connection with now.
The action in the past has a result now:
* “Where’s your key?” “I don’t know. I’ve lost it.” (I haven’t got it now)
* He told me his name but I’ve forgotten it. (I can’t remember it now)
* “Is Sally here?” “No, she’s gone out.” (she is out now)
* I can’t find my bag. Have you seen it? (do you know where it is now?)
We often use the Present Perfect to give new information or to announce a recent happening:
* Ow! I’ve cut my finger.
* The road is closed. There’s been ( = there has been) an accident.
* (from the news) The police have arrested two men in connection with the robbery.
You can use the Present Perfect with Just, Already and Yet:
Just = “a short time ago”:
* “Would you like something to eat?” “No, thanks. I’ve just had lunch.”
* Hello. Have you just arrived?
Already: we use already to say that something happened sooner than expected:
* “Don’t forget to post the letter, will you?” “I’ve already posted it.”
* “What time is Mark leaving?” “He’s already gone.”
Yet = “until now” and shows that the speaker is expecting something to happen. Use yet only in questions and negative sentences:
* Has it stopped raining yet?
* I’ve written the letter but I haven’t posted it yet.
Note the difference between gone (to) and been (to):
* Jim is away on holiday. He has gone to Spain. ( = he is there now or on his way there)
* Jane is back home from holiday now. She has been to Italy. ( = she has now come back from Italy)