4. You must see the headmaster.

-> You have to see the headmaster. ( must ≈ have to: phải làm gì )

5. Peter spent three hours repairing his house.

-> It took Peter three hours to repair his house. (cấu trúc: it takes sb + thời gian+ to do sth : nó tốn bao nhiêu thời gian để làm gì)

6. No one works harder than Barbara.

-> Barbara works the hardest. 

7. Nam didn’t go to school yesterday.

-> Nam was absent from school yesterday. (be absent from sth: vắng mặt khỏi ...)

8. The rooms in this hotel aren’t so comfortable as the rooms in that hotel.

-> The rooms in that hotel are more comfortable than the rooms in this hotel. 

9. He drives carefully. He never has accidents.

-> He is such a careful driver that he never has accidents. (cấu trúc : S + V + such + Adjective + Noun + that + S + V)

10. Listening to music at home is more interesting than going to the concert.

-> I prefer listening to music at home to going to the concert. (prefer doing sth to doing sth: thích làm cái gì hơn cái gì)

11. Learning English is very difficult for my brother.

-> It is very difficult for my brother to learn English. ( cấu trúc : it +be+adj for sb to do sth: nó như thế nào với ai để làm gì )

12. The visitor spoke so quickly that we could not understand what she said.

-> The visitor spoke too quickly for us to understand what she said. (cấu trúc: too +adj/adv for sb to do sth: quá ....... cho ai để làm gì)  
Có gì không hiểu bạn hỏi mình bên dưới nha 
Chúc bạn học tốt!!
Hy vọng bạn cho mình 5 sao và trả lời hay nhất nha