5．　 完成被动式to have been done

例如：The boy is said to have been sent to hospital yesterday.

4．　 被动式to be done

例如：The work is to be done soon.

3．　 完成式to have done

例如：He seemed to have cleaned the room.

2．　 进行式to be doing

例如：He seemed to be reading something at that time.

1．　 一般式to do

例如：I like to read English.

4.动词不定式与疑问词连用

疑问代词who, what, which和疑问副词when, where, how, why等后面可以接动词不定式，构成动词不定式短语，可以在句子中作主语、宾语、表语等成分。

例如：(1) He doesn’t know how to use the machine.

　　　　　　　　　　　　　　　　　 　　　　 (不定式作宾语)

　　　 　　　 (2) How to use the machine is a question.

　　　　　　　 　　　 (不定式作主语)

　　　 　　　 (3) The question is when to go there.

　　　 　　　　　　　　　　 (不定式作表语)

(二)动词不定式的时态和被动形式

动词不定式是非谓语动词的一种，由不定式符号(to)加动词原形构成。不定式的形式有五种：

3.动词不定式的否定形式

动词不定式的否定形式not + to + 动词原形

例如： He asked me not to make such a mistake.

6.　　　 作状语

He stopped to have a look.

5.　　　 作定语

I have nothing to say about that thing.

4.　　　 作宾语补足语

He told me to be here on time.