1. His questions can't be answered.
`->` Câu bị động với "can": S + can be + Vpp
2. He was sent abroad to study chemistry.
`->` Câu bị động quá khứ đơn: S + was/were + Vpp
3. Jim asked Tom if his parents were busy.
`->` Câu trần thuật yes, no: S + asked + O + If + S2 + V lùi thì
4. I haven't visited Thailand for 2 years.
`->` The last time + S + V2/ed + was + thời gian + ago = S + have/has + not + Vpp + for + khoảng thời gian
V
1. How long have you learnt English ?
`->` How long + have/has + S + Vpp ?
2. If you saw a UFO what would you do ?
`->` If 2: If + S1 + V2/ed, S2 + would + Vpp
3. He asked me when my school vacation started ?
`->` Câu trần thuật có từ để hỏi: S + asked + O + từ để hỏi + S + V lùi thì
4. Many programs were held during the Festival last July.
`->` Câu bị động quá khứ đơn: S + was/were + Vpp
