`-` BĐ :

`+` HTĐ : S + is / am / are + VpII ( by O )

`+` QKĐ : S + was / were + VpII ( by O )

`+` HTTD : S + is / am / are + being + VpII ( by O )

`+` HTHT : S + have / has + been + VpII ( by O )

`+` TLĐ : S + will be + VpII ( by O )

`+` TLG : S + is / am / are + going to be + VpII ( by O )

`21`.The room was filled by smoke

`22`.Is English taught here ?

`23`.Will she be invited to your wedding party ?

`24`.Were some exercises given by the teacher ?

`25`.Is a poem going to be written

`26`.Has the window of the laboratory been changed ?

`27`.Are big cakes being made for the party ?

`28`.Are inquiries about the thief being made by the police ?

`\text{# TF}`

`21.` The room was filled by smoke.

`->` Bị động quá khứ: S + was/were + V3/ed + by + O (khẳng định)

`22.` Is English taught here?

`->` Bị động hiện tại: Is/Are/Am + S + V3/ed + by + O? (nghi vấn)

`23.` Will she be invited to your wedding party?

`->` Bị động tương lai: Will + S + be + V3/ed + by + O? (nghi vấn)

`24.` Were the exercises given by the teacher?

`->` Bị động quá khứ: Was/Were+ S + V3/ed + by + O? (nghi vấn)

`25.` Is a poem going to be written?

`->` Bị động với "going to be": Is/Am/Are + S + going to be + V3/ed + by + O? (nghi vấn)

`26.` Has the window of the laboratory been changed?

`->` Bị động hiện tại hoàn thành: Have/Has + S + been + V3/ed + by + O? (nghi vấn)

`27.` Are big cakes being made for the party?

`->` Bị động hiện tại tiếp diễn: Is/Am/Are + S + being + V3/ed + by + O? (nghi vấn)

`28.` Are inquiries about the thief being made by the police?

Nếu chủ ngữ không xác định (they, somebody, someone, anyone, people,…) thì có thể lược bỏ trong câu bị động.