3 we have flown to Singapore for 5 years

-> S + have / has + vpii + for + 1 khoảng thời gian = it has + VPII + since + S + V thì QKĐ

4 i  haven't cut my hair since november

-> S + last + V2 + in + mốc thời gian = S + haven't / hasn't + VPII + since + 1 mốc thời gian

5 we haven't called each other for 5 months

-> the last time + S + V-ed + was + 1 khoảng thời gian = S + haven't / hasn't + VPII + for + 1 khoảng thời gian

6 we haven't met each other for a long time

-> S + haven't / hasn't + VPII + + for + 1 khoảng thời gian = it is a long time + since + 1 mốc thời gian

7 how long  long have you had it ?

-> how long + have / has + S + VPII

8 i haven't had such a delicious meal before 

-> this is the fisrt time + S + have / has + VPII = S + haven't / hasn't + VPII + before

9 the  last time I saw him was 8 days ago

-> the last time + S + V-ed + was + 1 khoảng thời gian = S + haven't / hasn't + VPII + for + 1 khoảng thời gian

10 he has been collecting stamp for five years

11 this is the first time she has talked to the foreign 

-> this is the fisrt time + S + have / has + VPII = S + haven't / hasn't + VPII + before

12 she hasn;t written for me since 2016

-> S + last + V-2 + in + 1 mốc thời gian = S + hasn't / haven't + VPII + since + 1 mốc thời gian

`3to` We have flown to Singapore for 5 years.

`4to` I  haven't cut my hair since November.

`5to` We haven't called each other for 5 months.

`6to` We haven't met each other for a long time.

`7to` How long have you had it?

`8to` I haven't had such a delicious meal before.

`9to` The last time I saw him was 8 days ago.

`10to` He has been collecting stamps for five years.

`11to` This is the first time she has talked to the foreign.

`12to` She hasn't written for me since 2016.