Bạn tham khảo bên dưới:

1/ Mark is too young to see the horror film.
⇒ Mark in not old enough to see the horror film.

* Cấu trúc : S + (not) Adj + enough
2/ They should quit smoking.
⇒ They had better quit smoking.

* Should = have better = ought to + Vinf
3/ They once started these machines by hand.
⇒ They used to start these machines by hand.

* Cấu trúc used to : S + (not) used to + Vinf
4/ Mary went shopping because she wanted to buy some jeans.
⇒ Mary went shopping in order to buy some jeans.

5/ She was sleeping and the fire started.
⇒The fire started when she was sleeping.

1. mark is too young to see the horror film

⇒mark is not old enough to see the horror film.

3. They once started these machines by hand.
⇒They used to start these machines by hand.

5.She was sleeping and the fire started

⇒ The fire started while she was sleeping.

2.They should quit smoking.
⇒ They had better quit smoking.

4.Mary went shopping because she wanted to buy some jeans.
⇒ Mary went shopping in order to buy some jeans.