Bị động:

`-` QKD: S + was/were + V3/ed 

`-` HTTD: S + am/is/are + being + V3/ed 

`-` HTHT: S + has/have + been + V3/ed 

Bị động kép:

`-` It + be ( chia theo v của V1 ) + PII của V1 + that + S2 + V2.

  Vd: People say that he is a famous singer.

   `=>` It is said that he is a famous singer.

`-` S2 + be( chia theo V1 ) 

`+` To verb ( vế 2 chia TLĐ )

`+` To be Ving ( vế 2 chia HTTĐ )

`+` To have PII ( vế 2 chia HTHT, QKHT, QKĐ )

`+` to have been PII ( vế 2 chia bị động của HTHT, QKHT, QK Đ )

Answer:

`=>` It is known that David left New York last week

`=>` David is known to have left New York last week.

`=>` It is known that David left New York last week.

`-` Bị động Kép : It is + V3/ed + that + S + V

`-` It was + VpII + that + S2 + V2

`=>` David is known to have left New York last week.

`-` Bị động đặc biệt : S + to be + known + to have + P2.

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