由不及物动词+介词或副词形成的被动语态

Many trees are cut down by workers.

许多树木被工人砍倒。

不及物动词不能跟宾语,当然就没有被动语态了,但有的不及物动词,后面跟上一个介词或副词后(即形成所谓的动词短语),其作用和一个及物动词一样,这样,在变成被动语态时,千万不要把介词或副词去掉。

例如:

She looks after them.

她照顾他们。

(○)They are looked after by her.

(×)They are looked by her.

We laughed at him.

我们笑话他。

He was laughed at(by us).

 

动词短语的被动语态

take care of(照看)→be taken care of

cut down(砍倒)→be cut down

laugh at(嘲笑)→be laughed at

look after(照料)→be looked after

 

被动语态的动词短语

以下这些短语本身即是被动语态的形式,不需再加“by”。

be covered with                  用……覆盖着

be surprised at                    对……感到惊奇

be known to                       出名

be interested in                  对……感兴趣

be made of(from)          用……制造的