My question is why native speakers use the present perfect in the second part of the sentence "Have you seen him?" instead of "Did you see John?" Could any native speaker or instructor, from the United Kingdom specifically, help me? Thanks in advance. .................... I know that you didn't ask for corrections, but your text looked so horrible without any punctuation or capital letters that I couldn't help correcting it. We don't just use punctuation and capitals to 'look nice' - they are essential features of the written language, and you really do need to use them! They aren't optional. Now to your question. Whenever we use the present perfect we are giving information about a present situation. The present perfect tells us about something which has happened, or hasn't happened, and this event ( or non-event) always has a result in the present time. In your example, the speaker is looking for John at the moment. He needs to see John now, but he can't find him. This is why he asks the other person 'Have you seen John?'. For example: 'I haven't seen John. Have you seen him?' 'No, I haven't. I think he's gone to London.' This conversation is all about the situation now: the fact that the first speaker wants to see John but doesn't know where he is, and the fact that John isn't here because he is in London at the moment. This is different from the past tense form 'Did you see John?'. You would use this to talk about a finished period of time some time in the past which has already been mentioned. For example: 'Did you go to the football match yesterday evening?' 'Yes, I did.' 'Did you see John?' 'No. He wasn't there.' I hope that helps.

Use of the present perfect implies an action that started in the past and continues to the present, so "have you seen him" covers a period of time, while "did you see him" refers to a specific point in time or a specific event. Sorry, I'm not from the UK

The present perfect doesn't need a 'time reference'. Look at the difference between the following. I haven't seen Mahmoud. - By the use of the present perfect, we know this is recent. It doesn't need a time reference. You know that I mean 'I haven't seen Mamoud recently. I didn't see Mamoud last week. If I say 'I didn't see Mamoud', it sounds unfinished. You need to ask, when didn't you see him? I must echo the comments of Su.Ki. who mentioned the use of correct punctuation. The use of capital letters at the start of sentences is not optional. And the pronoun 'I' must always be capitalized. It looks very bad otherwise. It is a very bad habit to get into. Your reply to her continued to ignore this which suggested that you hadn't accepted the importance of her good advice.