1. The blue shirt isn't as expensive as the red shirt.
→ so sánh ngang bằng: S + is/am/are + not + as + Adj + as + S
2. What about going to the cinema?
→ Why don't we + V0 = What about/How about + V_ing = Let's + V0 = suggest + V_ing: đề nghị làm việc gì
3. This book must be returned to the library.
→ câu bị động dạng động từ khiếm khuyết: S + must/can/should/could/shall .. + be + V3/ed + (by+O)
4. Nam told us not to talk in class.
→ S + told + O + (not) to_V: yêu cầu ai đó (không) làm gì
5. It took us three hours to repair this room.
→ S + spend(s)/spent + time + V_ing: Ai đó dành ra bao nhiêu thời gian để làm gì
= It + takes/took + time + to_V