`1.` It is 5 years since I last visited my grandparents.

`->` I haven’t visited my grandparents for 5 years.

`2.` It’s years since she wrote to me.

`->` She hasn’t written to me for years.

`3.` I haven’t cheated in exam for years.

`->` The last time I cheated in exam was years.

`->` It is years since I last cheated in exam.

`4.` He hasn’t smoked for 2 years.

`->` The last time he smoked was 2 years ago.

`->` It is 2 years since he last smoked.

`5.` I haven’t met her for 5 days.

`->` I last met her 5 days ago.

`->` The last time I met her was 5 days ago.

`6.` I haven’t gone to school for 4 months because of covid-19.

`->` The last time I went to school was 4 months ago.

`->` It is 4 months since I last went to school.

`7.` I haven’t seen Anna for 10 days.

`->` The last time I saw Anna was 10 days ago.

`8.` When did you have 10 scores in Math?

`->` How long have you had 10 scores in Math?

`9.` When did you buy that bag?

`->` How long have you bought that bag?

`10.` It is 5 years since I last visited my grandparents.

`->` I haven’t visited my grandparents for 5 years.

`11.` When did you start loving him?

`->` How long have you loved him

`12.` It’s years since she wrote to me.

`->` She hasn’t written to me for years.

    Cách giải

Form:  S + have/has + not + VpII + for + time

`⇔` It is + time + since + S + (last) + V-ed

`⇔` S + last + V-ed + time + ago

`⇔` The last time + S + V-ed + was + time + ago

Form: S + started/began + doing sth + time + ago

`⇔` S + have/has + VpII + for + time

Form: When did + S + V?

`⇔` How long + have/has + S + VpII?