1. Unspecified point in the past
I have been to Spain three times.
(At some unspecified time in the past, I went to Spain).
Compare with the simple past:
I went to Spain three times in 2005.
(specified time in the past – the year 2005)
2. An action that occurred in the past, but has a result in the present (now)
We can’t find our luggage. Have you seen it?
(The luggage was lost in the past, do you know where it is now?)
3. Talking about general experiences (ever, never)
It usually refers to an event happening at some moment in your life.
Has she ever tried Chilean wine before? (in her life)
I’ve never eaten monkey brains before. (in my life)
4. Events that recently occurred (just)
Do you want to go to a restaurant with me?
No, thanks. I’ve just eaten lunch. (I recently ate lunch.)
5. Events that have occurred up to now (yet)
Are Carlos and Rodrigo here? No, they haven’t arrived yet. (they’re still not here now)
6. Events that occurred before you expected (already)
I’ve already graduated from University. (I expected to graduate at a later date.)
7. Events that began in the past and haven’t changed (for, since)
Mike has worked at Woodward for 3 years.
(Mike started working at Woodward 3 years ago and he still works there now.)
Julie has worked at Woodward since September last year.
(Julie began working at Woodward in September of last year, and that hasn’t changed – she still works here now.)