$20.$ I had been sent those letters by a young man.

- Câu bị động thì quá khứ hoàn thành: S + had + been + V (P_II) + (by O).

$21.$ How often do you have your car serviced by the mechanics?

- have something + V (Pii) + by O: có thứ gì được làm bởi ai.

- Thường dùng câu bị động này để chỉ sự nhờ vả.

- Do/ Does + S + V (Bare)?

$22.$ Have you had your hair done by somebody?

- have something + V (Pii) + by O: có thứ gì được làm bởi ai.

- Thường dùng câu bị động này để chỉ sự nhờ vả.

$23.$ They are going to have the room painted next week.

- Giống như câu $22$ ạ.

$24.$ A lot of exercises were given to me by the teacher last week.

- Câu bị động thì quá khứ đơn: S + was/ were + (not) + V (P_II) + (by O).

$25.$ A lot of information was sent to you by your company yesterday, didn't it?

- Câu bị động thì quá khứ đơn: S + was/ were + (not) + V (P_II) + (by O).

`20.` I had been sent those letters by a young man

`-` Bị động QKHT, form : S + had + been + Vp.p + ..+ by sb + ...

`21.` How often do you have your car serviced by the mechanics

`22.` Have you had your hair done by somebody

`-` Bị động nhờ vả: S + have sth + Vp.p + by O

`23.` They are going to have the room painted next week

`24.` A lot of exercises were given to me by the teacher last week

`25. `A lot of information was sent to you by your company yesterday, didn't it

`-` Bị động QKĐ ( câu 24,25 ),form: S + was/were + Vp.p + ... + by O