`12.` If she isn't more hard-working, she will get low marks.

`@` If `1`:

If + HTĐ, + S+ will /can/should + V-inf+O

`@` Unless = If ... not : Trừ khi 

`13.` If he doesn't listen to his parents, he will fail.

`@` Tương tự câu `13`

`14.` They have watched the movie for one hour.

`@` S+ began/stated + V-ing+O+ khoảng thời gian + ago.

`->` S+ has/have+ not+ V-pp (+O) + for + khoảng thời gian.

`15.` He hasn't cried for ten years.

`@` S + last + V2/V-ed (+O) + khoảng thời gian + ago.

`->` S+ has/have+ not+ V-pp (+O) + for + khoảng thời gian.

`12)`

`to` If she isn't more hard - working, she will get low marks.

`@` Cấu trúc ĐK loại `1`

`-` It + V(HTĐ), S + will/can/should + V(nt) + O

`-` Unless `=` if not

`13)` 

`to` If he doesn't listen to his parents, he will fail

`@` Cấu trúc: câu `12)`

`14)` 

`to` They have watched the movie for one hour.

`@` Cấu trúc HTHT:

`( + )` S + have/has + Ved/Cột `2` + O

`15)`

`to` He has not cried for ten years 

`@` Cấu trúc thì HTHT:

`( - )` S + have/has + not + Ved/Cột `2` + O

`-` for + khoảng thời gian

`#Ph`