I would like to ask if the following sentences have different meanings. lately I've been overthinking about tenses which I've been using fluently my whole life. Specifically present perfect
Context: Say I was talking to a friend about what happened this month. It was a pretty boring month, so I just tell him about something surprising that happened: A happy one-off encounter with a stranger.
Friend: "Has anything interesting happened to you this month?
Me: "Well, nothing much. Oh, but I met a guy at the university who has told me my hair looks fantastic"
Does this strongly differ in meaning from just saying:
"but I met a guy at the university who told me my hair looks fantastic"
My own deduction weakly says something along the lines that "has told" emphasizes that I am still happily surprised about that, whereas just "told me" is more neutral and focuses on the fact that I met a guy (who just so happened to also compliment me). I guess the present perfect could also technically mean that he told it to me sometime after I met him.
Furthermore, this might warrant its own question, but does the meaning change if "met" is changed to "have met". i.e.
"but I have met a guy at the university who has told me my hair looks fantastic"
I think this might imply that we kept meeting/chatting later. Is there a preference for present perfect or simple past for events that happened "this month"? This source would suggest so (if you scroll down to "Time Expressions with Present Perfect")
English is not my native language, and in my own language I would probably use the simple past + simple past equivalent. However, in English present perfect is used for experiences and/or indefinite time (such as "this month"), which makes me wonder whether it should be used here.
Best Answer
You are right that the present perfect is common with expressions of unfinished time such as "this month". The question in your short dialog (Has anything interesting happened to you this month?) uses the present perfect for this reason.
But your answer sets up a new time context, so the use of the present perfect in the question is not relevant.
The context of your answer is a moment of finished time, in which you met someone and they told you something. The past tense is the most natural choice for actions that were completed in finished time.
I understand your uncertainty in view of the continuing surprise you feel at the compliment, since the present perfect is commonly used for the present results of a past action. But the present perfect in this case (has told me...) just sounds wrong to me as a native speaker.
As to your second question. It is feasible to use the present perfect if you are listing things that have happened to you this month:
Alternatively, as Kate Bunting pointed out in the comment, you can use the present perfect to imply that you are still in contact with the person.
If it's any consolation, the perfect aspect causes problems for even expert non-native speakers of English, as you appear to be. Endley in Linguistic Perspectives on English Grammar (p251) calls the perfect "especially troublesome".
You might be interested in reading the excellent canonical post on the present perfect on ELU's sister site English Language and Learning.