动词不定式的用法讲解及练习题 北 京 四 中

北 京 四 中

撰稿老师：黄 浩 编审老师：蔡正礼 责任编辑：丁 华

动词不定式的用法讲解及练习题

不定式既具有动词的一些特征，又具有名词，形容词和副词的句法功能 否定式：not +不定式 不定式的时态

一般说来，不定式一般式表示的动作有时与限定动词表示的动作同时发生，也有时发生在限定动词表示的动作之后。如： Who heard him say that? He seems to know this. I hope to see you again.

不定式进行式表示动作正在进行，通常与限定动词表示的动作同时发生，如： They are said to be building another bridge across the river. I happened to be going that way too.

不定式完成式表示的动作发生在限定动词表示的动作之前，如： I am sorry to have given you so much trouble. I am glad to have seen your mother. 不定式的句法功能： （1）作主语

To talk with him is a great pleasure.

不定式短语作主语时，为了保持句子的平衡，往往以it作形式主语，而把不定式短语置于谓语动词之后，如：

It's nice to hear your voice. （2）作表语

Her wish is to become an artist. （3）作宾语

常用于及物动词: want , hope, wish, like, need, hate, offer, prefer, begin, start, attempt, decide, determine, expect, promise, pretend, refuse ,afford, manage, help等之后，如：

You should continue to learn as long as you live.

注1：如果作宾语的不定式又有自己的补语，则须用先行词it 作形式宾语，而将真正的宾语不定式后置，如：

They found it impossible to get everything ready in time.

注2：不定式一般不能作介词的宾语，只有在极少数介词如:but, except等后边才行。此时不定式可以带to或不带to,如：

In very cold winter weather a cold-blooded animal has no choice but to lie down and sleep.

There was nothing left to do but clean the windows.(前边有do, to 省略) 但“疑问词+不定式”结构可以作介词的宾语，如： I have no idea about what to do next. （4）作宾语补足语

通常用于及物动词或动词短语：want ,wish, ask, order, beg, tell, permit, know, help, advise, persuade, allow, prepare, cause, force, require, call on, wait for等之后，如：

The teacher asked the students to hand in their homework. （5）作定语

不定式作定语时，须放在被它修饰的名词或代词之后。被修饰的名词或代词往往是不定式的逻辑宾语。

I have a lot of work to do.

当作定语的不定式所修饰的名词或代词是不定式动作的承受者时，不定式既可用主动语态，又可用被动语态，但其含义有所不同。所以如果修饰名词的不定式的动作是主语作的, 不定式用主动。

试比较：

Have you anything to send?

你有什么东西要寄吗？(不定式to send 的逻辑主语是you) Have you anything to be sent?

你有什么要(我或别人)寄的东西吗？(不定式to be sent的逻辑主语是已被省略的me或someone else)

I've got letters to write. He has something to say to you. （6）作状语

作修饰动词的目的状语

We must do everything we can to help them. 作修饰动词的结果状语

加强意料不到的语气，在表示结果的不定式前还可加only，如： I went to see him only to find him out. 作修饰表语形容词的状语: 修饰形容词的不定式用主动: The chair is comfortable to sit in. 作结果状语或程度状语。

too+形容词(或副词)+to do 太-----(以致)不能(做) It is too dark for us to see anything in the room. 形容词(或副词)+ enough +to do -------足以(做) Is the boy old enough to go to school? （7）作独立成分 To tell you the truth To cut a long story short

To begin with (首先)

不定式的复合结构“for+名词(或代词宾语)+to do sth.”

这种结构中的for本身无意义，for后的名词或代词(宾格)是不定式的逻辑主语 This is for you to decide. 句型1：It is + for sb. to do sth. 句型2：It is + of sb. to do sth.

good, kind, nice, wise, unwise, clever, silly, stupid, foolish, right, wrong, rude, impolite, careless, naughty等 不定式省去to的情况

（1）当两个或两个以上的不定式并列在一起时，第一个不定式带to ，后面的不定式往往把to省去。如：

I wished to finish my homework and (to )get away. 但是，如果是在对照的场合，则不可以省去 “to”，如： It is better to laugh than cry. (wrong)

（2）在感官动词see, hear, feel, watch, notice, observe, listen to ,look at和使役动词let, make, have的复合宾语中，不定式须省去to。如： I am a doctor. Let me examine you.

（3）在help的复合宾语中，不定式可以带to也可以不带to. He often helps me (to)do my home work.

（4）had better, had best, would rather, would rather--- than, cannot but , --- You'd better remain where you are. 精选练习 Ⅰ、翻译句子

1. ________________________________(保卫祖国) is our sacred duty. 2. It is an honor __________________________(全心全意为人民服务). 3. It was not correct ________________________(那样谈话).