1. The red car is more expensive than the black car.

cấu trúc so sánh hơn: S1 + V + adj ngắn ( more adj dài ) + than + S2 + V

2. The play is more interesting than this film.

cấu trúc so sánh hơn: S1 + V + adj ngắn ( more adj dài ) + than + S2 + V

3. Jack is the same age as my son

cấu trúc giống như:  The same + adj + as

4. Because Mary was sick, she could not go to school

Cấu trúc bởi vì: Because S + V ( nguyên nhân), S+V ( kết quả)

5. I haven't met him for 3 months.

cấu trúc hiện tại hoàn thành: S + have/has + Not + V3/ed + for + time (= The last time + S + V2/ED + was + time...)

6. Lan finished her homework so she went out

cấu trúc vì vậy: S + V ( nguyên nhân), so S+V ( kết quả)

7. He enjoys doing morning exercise 

cấu trúc: enjoy + Ving

8. câu này mình ko biết làm hoặc có lẽ bạn lộn

9. It's a good idea to walk around the Old Quarter at night.

cấu trúc: It's a good time + to V1

1, The black car is not so expensive as the red car

=>the red car is more expensive than the black car. 

2, This film is not so interesting as the play =>the play is more interesting than this film. 

3, Jack is 13 years old and my son is, too =>Jack is the same age as my soon. 

4, Mary was sick, so she could not go to school => because Mary was sick, she could not go to school.

5, The last time I met him was 3 years ago => I haven't met him for 3 years.

6, Lan went out because she finished her homework => Lan finished her homework, so she went out

7, He is interested in doing morning exercise

=> He enjoys doing morning exercise. 

8, We have learned English for 3 years

=> We have been learning English for 3 years

9, You should walk around the Old Quarter at night

=> It's a good idea to walk around the Old Quarter at night.