Actions completed in the recent past (but not in the finished period of time, this is very tricky!):
He has recently been to England. Now he is back in New York.
(been to because been is associated with the verb go to, so we don’t use in)
He has recently gone to London. He is there now
She has just returned from New York. I haven’t seen him lately. Have you already finished your homework? Has it stopped raining yet? I haven’t found the book yet!
Very recent actions!
Here is the hit: with very recent actions, yes, we can use this term, sometimes, with very recent actions, we can use Both Past Simple and Present Perfect:
She just left
She has just left
In a nutshell (exceptions may apply)
We use Present Perfect when we have:
just / recently / lately , already and yet can also express not only the completeness, but recentness
I have heard many times native speakers say:
What did you just say?
That’s because the speaker is not interested in the action (it was said or it wasn’t), but they want to know what was said rather then it was said or not said at all. Please, refer to the lesson “When we don’t use Present Perfect.”
Some verbs, such as say, tell, ask, understand etc usually go with Tthe Simple line of tenses:
Did you already tell him about it?
Did you understand what I have just told you? In this example, a time period when the understanding process took place is implicitly meant to be over, a second ago before the speaker finished their exhalations and asked this question. That is why the Past Simple was used here.
I can also say that in modern English the complexity of Present Perfect is simplified to the simplicity of Past Simple, what I want say is that many times you can just substitute Present Perfect with Past Simple or use both when it comes to recentness of the action:
No, thank you, I just had my lunch.