Viết lại câu dùng từ gợi ý: 1) When did you study English? 2) How long ago did you learn music? 3) He learnt English when he was 18

1.When did you study english ?
-> how long.....................?
2.how long ago did you learn music ?
->how long have .............?
3.he learnt english when he was 18
->he has...............
4.lan hasn't written to Maryam for a month
->lan didn't ...................
5.i haven't met her for a long time 
-> i didn't............................
6.i saw her 10 years ago 
​-> i haven't ................................