Question

I haven't seen you for a long time. Why present perfect?​

Answer 1

Answer:

The sentence is in present perfect, because the identification of a present perfect tense is that it uses 'have' or 'has' as an auxiliary verb, and the above sentence does make use of a 'have'.

Hope that helps...

Answer 2

The present perfect tense is used to talk about an action that started in the past and is still ongoing or that has just finished. In this case, the present perfect is used to talk about a period of time that started in the past and is still ongoing, or "for a long time".

For example, the phrase "I haven't seen you for a long time" can be translated as "I haven't seen you for a long time" and can be used to talk about a period of time that started in the past and is still ongoing.