1.  The book was too complicated for us to understand.

`-` S + to be + so + adj + that + clause 

`=>` S + to be + too + adj + (for sb) + to + V-inf

2. Anne asked where she could find the tourist office.

`-` Câu gián tiếp wh-questions : S + asked + smb + wh/how + S + V(lùi thì) + O

`-` I `->` she

`-` can `->` could

3. Had he done his homework , he wouldn't have been punished by the teacher.

`-` Because + clause , clause : Bởi vì

`-` Đảo ngữ ĐK loại 3 : Had + S + V3/ed + O , S + would + have + V3/ed

4. He is believed to have driven through the town at 90 km per hour

`-` People + V1 + that + S2 + V2

`=>`+` Bị động kép : S2 + to be + V3/ed + to + have + V3/ed (nếu V2 xảy ra trước V1)

5. No matter how busy Tim's father was , he still spent time playing with him

`-` Though + clause , clause : Mặc dù ... , nhưng ..

`=>` Đảo ngữ : No matter how + adj + S + to be , clause

6. Nam offered to clean the windows for Mai.

`-` offer + to V-inf : đề nghị làm gì đó

`-` for + sb : cho , hộ ai đó

7. My sister wishes she hadn't bought a second-hand car

`-` S + regret + V-ing : Ai hối hận vì đã làm gì

`=>` Câu điều ước ở quá khứ : S + wish(es) + S + had + (not) + V3/ed