=>
1. I have taught English for three years.
-> chuyển QKĐ sang HTHT, S have/has V3/ed, for + khoảng thời gian
2. It is ten years since I last went to HCM City.
-> It is + time + since S (last) V2/ed
3. Tired as he was, he tried to help me with my homework.
-> Adj as S tobe : mặc dù
4. I was not rich enough to buy the car.
-> adj enough to V : đủ...để
5. I haven't been to New York before.
-> S have/has not V3/ed before ~ It's the first time + HTHT
6. Hung accused his sister of damaging his camera.
-> accuse sb of Ving : buộc tội ai
7. It was not until this summer that we had some holidays.
-> It was not until .... that S V2/ed (quá khứ)
8. Had you not studied hard, you would have failed the exam.
-> đảo ngữ đk loại 3 : Had S (not) V3/ed, S would have V3/ed
9. He shouldn't have bought that house.
-> should (not) have V3/ed : lẽ ra (không) nên
10. I've never seen a better film than this film.
-> S have/has never V3/ed a + tính từ so sánh hơn + than this N