英語的動詞有兩種語態形式，即主動語態和被動語態。如果主語是動作是執行者，謂語動詞用主動語態。如果主語是動作的對象，謂語動詞用被動語態。如：
They build this school.
They school is built by them.
1、被動語態的構成
「助動詞 +(及物動詞的)過去分詞」構成動詞被動語態的形式。助動詞be有人稱、數和時態的變化，其變化規則與be作為系動詞的變化完全一樣。如：
This kind of TV set is made in Guangzhou.(一般現在時)
The thief was arrested.(一般過去時)
A new road is being built outside my house.(現在進行時)
The man was being questioned by the police.(過去進行時)
Your wallet has been found.(現在完成時)
By the time we got there. The work had been finished.(過去完成時)
My sister would be taken care of by grandma.(過去將來時)
Your watch will be repaired.(一般將來時)
教學難點：
在英語裡，有一些動詞是不及物動詞，後面不能跟賓語，所以沒有被動語態。以下動詞只有主動語態，沒有被動語態。
appear, die, happen, fall, arrive.
2、五種時態的被動語態舉例
① 一般現在時
A lot of books are kept in our school library.
Radio is used in everyday life.
② 一般過去時
A thief was caught last night.
They were asked to speak at the meeting.
③ 現在進行時
A new library is being put up in their school now.
The watch is being repaired.
④ 一般將來時
The class meeting will be held next Saturday afternoon.
The thieves will be arrested.
⑤ 現在完成時
My bag has been stolen.
Many stamps have been collected by me since last year.
3、主動語態變被動語態
① 主動結構的賓語變為被動結構的主語。
② 主動結構的謂語動詞由主動語態變為被動語態。
③ 主動結構的主語變為介詞by的賓語，組成介詞短語，放在被動結構中謂語動詞之後。在動作的執行者無須說明或不必強調時，by短語可以省略。
④ 主動語態、被動語態兩種時態要保持一致。如：
We repaired the motor.
The motor was repaired by us.