4、 主语补语，说明主语所处的状态。例如：

　　e.g. The door was found locked.

　　 The car lay in the pit, broken.

　　　　The questions discussed have not been made known to us yet.

注、在上述结构中，有些动词如get, have, want, like, wish等作谓语时，该种句子不能转换成被动句。在能转换成被动语态的句子中，原来的宾语补足语就变成主语补足语。

C、现在分词和过去分词的区别

现在分词和过去分词的区别主要在于"时间"和"语态"两个方面：

1、时间区别

一般来说，现在分词表示正在进行的动作；过去分词表示已经完成的动作。

　比较：falling flowers正在飘落的花； fallen flowers落花（已落下的花）

　　boiling water正在沸腾的水； boiled water已烧开过的水

　　Ours is a developing country and theirs is a developed country .

　　　　我们的国家是一个发展中国家，而他们的国家是发达国家。

　　He found the city changing every day .

　　　　他发现这座城市每天都在变。

　　He found the city greatly changed .

　　　　他发现这座城市大大地改观了。

2、语态区别

现在分词表示主动的意思，所修饰的人或物是分词动作的执行者；过去分词则表示被

动的意思，所修饰的人与物是分词动作的承受者。

比较：an exciting speech一个激动人心的报告(= a speech that excites people )

excited audiences 激动的观众(= audiences who are excited by ---)

the surprising news 令人吃惊的消息(= the news that surprises people )

the surprised boy 受了惊吓的男孩(= the boy who is surprised by ---)

a moving film 一部感人的影片(= a film that moves people )

the moved students 受感动的学生们(= the students who are moved by ---)

She heard someone closing the door. 她听见有人在关门。（主动）

　　　　She heard the door closed. 她听见门被关上了。（被动）

过去分词练习

I.用过去分词合并两句句子

1. Alice entered the living room. Alice was followed by her boyfriend.

2. The doctor is well known for his medical knowledge and skills.