Teacher: Can you explain to me when you......... the Past Simple and when the Present Perfect?

Student: I think the past simple is for a......... time in the past and the present perfect is when you don't know when it was.

Teacher: Excellent. Now if I wanted to describe my time in Paris in 1999 with the verb 'stay', what ......... I say?

Student: I think it is I stayed in Paris in 1999. Is that all ......... ?

Teacher: Absolutely perfect. Now what......... the Present Perfect Continuous?

Student: That's one I never understand......... hard I try.

Teacher: Well if you started living in Paris in 1999 and you are still there, you say; I have been living there ......... 1999.

Student: Yes, I see I think I understand but you have ......... many tenses in English!

Teacher: Right ......... one more. Tell me which form you use if you are going to leave Paris and you tell someone about the length of time from your arrival till now.

Student: Oh, that's easy. I say: I have lived here for 6 years. I can see from the......... on your face I am right.