Compare the past form and have -en
We use the past form to talk about a specific time in the past.
We use have/has + -en to talk about results we have in the present.
I went to Africa last year .
He didn’t eat lunch yesterday. Lunch time was in the past.
Did you do your homework? (in the recent past)
I‘ve been to Africa.
He hasn’t eaten lunch. (not yet: he may eat it in the future)
Have you done your homework?
We often ask questions with have/has + -en. We don’t know which time in the past to talk about so we talk about the present. We then use the past form to get the specific details.
A: Have you been to Africa? (interested in experience that you have in the present)
B: Yes, I went there last year. (giving details about when I got this experience: in the past)
We use the past form to talk about a period of time that finished in the past.
We use have/has + -en with a period of time up to the present.