`11.`She has written for 30 minutes.

`12.`They have studied English since they were in grade 3.

`=>`Cấu trúc viết lại câu `11,12` : S + started/began + Ving/to V + time

`=`S + have/has + Vpp + since/for + time 

`13.`I haven't seen him for 3 weeks.

`14.`I haven't watched this movie for 6 months.

`=>`Cấu trúc viết lại câu `13,14` : S + last + V2/ed + time

`=`The last time + S + V2/ed + was + time

`=`S + have/has not + Vpp + since/for + time

`=`It's + time + since + S ( last ) + V2/ed

`16.`How long have you read this book ?

`=>`When + did + S + V bare ?

`=`How long + have/has + S + Vpp ?

Đáp án:

`11,` She has written for `30` minutes.

- Cấu trúc `:` S + started / began + to V / Ving + time trong QK `( 11 ; 12 )`

$→$ S + have / has + V3 / PII + since + mốc thời gian / for + khoảng thời gian

`12,` They have studied English since they were in grade 3.

`13,` I haven't seen him for `3` weeks.

- Cấu trúc `:` S + last + V2 / V-ed + time trong QK `( 13 ; 14 )`

`->` The last time + S + V2 / V-ed + was + time trong QK

`14,` I haven't watched this movie for `6` months.

`16,` How long have you read this book?

- Cấu trúc `:` When + did + S + V ?

`->` How long + have / has + S + V3 / PII ?