=>

11. Our children were looked after by her when we were out.

-> bị động QKĐ was/were V3/ed

12. This room hasn't been used for ages.

-> bị động HTHT have/has (not) been V3/ed

13. The dog was hit in the garden by the boy yesterday.

-> bị động QKĐ was/were V3/ed

14. By whom was this book written?

-> bị động QKĐ Was/were S V3/ed?

15. By whom has this room been cleaned?

-> bị động HTHT Have/has S been V3/ed?

16. Considerable damage has been caused by the fire.

-> bị động HTHT have/has (not) been V3/ed

17. Several new proposals are being considered by the committee.

-> bị động HTTD is/am/are being V3/ed

18. This letter may not be opened, may it?

-> bị động may (not) be V3/ed

-> câu hỏi đuôi (vế giới thiệu phủ định -> câu hỏi đuôi khẳng định)

19. She was bought a present on her birthday.

-> bị động QKĐ was/were V3/ed

20. He has been told to report for duty at 6 p.m.

-> bị động HTHT have/has been V3/ed

${11.}$ Our children were looked after by her when we were out.

→ bị động QKĐ: S + was/were (not) + V3/ed + (by+O) + time

${12.}$ This room hasn't been used for ages.

→ bị động HTHT: S + have/has (not) + been + V3/ed + (by+O) + time

${13.}$ The dog was hit in the garden by the boy yesterday.

→ bị động QKĐ

${14.}$ Who was this book written by?

→ bị động QKĐ

${15.}$ Who has this room been cleaned by?

→ bị động QKĐ

${16.}$ Considerable damage has been caused by the fire. 

→ bị động HTHT

${17.}$ Several new proposals are being considered by the committee.

→ bị động HTTD: S + is/am/are (not) + being + V3/ed + (by+O) + time

${18.}$ This letter may not be opened, may it?

→ bị động dạng động từ khiếm khuyết: S + can/could/should/must/may ... (not) + be + V3/ed + (by+O) + time

${19.}$ She was bough a present on her birthday.

→ bị động QKĐ

${20.}$ He has been told to report for duty at 6.00pm.

→ bị động với "told" thì HTHT:

- It + has told + that + S2 + V2 + O2

- S2 + have/has + been + told + to_V + O2