84. they said that I am a teacher

--> I was said to be a teacher

85. people said that Nam killed his wife

--> Nam was said to kill his wife

86. Does he often help you?

--> Are you often be helpped by him?

87. What is she doing?

--> what is being done by her?

88. She bought a new car yesterday

--> A new car was bought by her yesterday

89. People thought that she is a robber

--> she is thought to be a robber

90. my father often buys me perents on my birthday

--> I am often bought presents on my birthday by my father.

Cấu trúc câu bị động chung

S + tobe + Ved/PII+.....+ by sb

Cấu trúc câu bị động khách quan:

S + tobe + thought/said/...+ to + V(bare).....