英语动词不定式用法详解

杨正仁

【摘要】非谓语动词是由动词变来但不能作谓语的一种形式，但可以带自己的宾语或状语，构成非谓语动词短语。非谓语动词之不定式在句中作主语、宾语、定语、状语、补语和表语，同时动词不定式也有时态、语态和否定形式。

【关键词】动词不定式 句法功能 时态语态 否定式 疑问词+不定式 省略

非谓语动词是由动词变来但不能作谓语的动词形式，但可以带自己的宾语或状语，构成非谓语动词短语。不定式是最常用的非谓语动词之一，下面从句法功能、时态和语态等方面举例说明其用法。

一、句法功能

动词不定式具有名词、形容词和副词之特性，同时也保留动词特征，同自己的宾语和状语一起构成不定式短语，在句中作主语、宾语、定语、状语、补语、表语。

1.作主语

To love and to be loved are both happiness.

（1）不定式作主语时，为了避免头重脚轻，常用it作形式主语，不定式作真正主语，常见句型有：

It is very nice to get up early and do morning exercise.

It is a great honor to make a speech at the meeting.

It took me five hours to finish my homework yesterday.

It is against my will to tell her the secret.

（2）不定式的逻辑主语用of或for引出。用for时，它前面的形容词说明不定式的性质，而不是说明逻辑主语，常见的形容词有：important， necessary， difficult等；用of时，常用表示人的品质的形容词，常见形容词有：nice， good， cruel， typical， silly， foolish， stupid， bright， clever， wise， right， wrong， mistaken等，也可以用“逻辑主语+系动词+该形容词”模式改写：

It is very important for us to fasten safety belts.

It was silly of her to believe what he said = She was silly to believe what he said.

2.作宾语

（1）agree， beg， choose， decide， afford， fail， expect， hope， long， offer， manage， plan， prepare， pretend， strive， refuse， intend， promise， seem， wish， want等后常跟不定式作宾语。不定式一般不作介词宾语，但可以作but， except的宾语：

My parents agreed to send me abroad for holidays if I passed the exam.

He had no choice but to have a rest at home.

（2）like， love， hate， continue等动词后跟不定式和动名词作宾语意义接近，区别在于不定式表示具体的动作，动名词表示抽象概念：

I like reading， but I dont like to read in the classroom today.

（3）不定式作宾语时，用it作形式宾语，常跟一个形容词或者名词作宾补：

We consider it necessary to learn English well in case you go abroad.

We have made it a rule not to watch TV during dinner time.

3.作定语

（1）作定语时，与被修饰词之间有逻辑上的“主谓关系”、“动宾关系”等：

He is always the first to come and the last to go. （主谓关系）

I have a very important meeting to attend this afternoon. （动宾关系）

I will go to Shanghai. Do you have anything to be taken there？ （主谓关系）

注：此句中you不是不定式逻辑主语，故anything就成逻辑主语，anything与take之前构成被动关系，故用被动形式，但也可用主动形式：

I will do some washing. Do you have any clothes to wash （to be washed）？

There is a lot of homework to do （to be done） today.

（2）如果作定语的动词不能与被修饰词之间构成动宾关系时，要加相应的介词，构成介宾关系：

I have bought a pen to write with and some paper to write on.

（3）某些抽象名词ability， way， need， possibility， determination等后也跟不定式作定语：

The girl has the ability to operate this modern machine.

He has showed the determination to finish the work ahead of time.

4.作状语

不定式作状语时，通常表示原因、目的和结果，逻辑主语通是句子的主语，有主动和被动之分：

I was very pleased to hear the satisfactory news. （原因）

In order to go to college， I have to learn English well. （目的）

The question is very difficult to answer. =To answer the question is very difficult.

注意：不定式在这种情况下作状语，一般是及物动词，与主语之间是逻辑上的动宾关系，翻译为“…起来”，不用被动式：

The woman is very difficult to deal with.= To deal with the woman is very difficult.

He woke up at midnight， only to find the door was open.（结果）

He hurried to the school， only to be told that in was Sunday. （结果）

注意：分词也可作结果状语，但不定式的主动和被动形式都表示出乎预料的结果，而现在分词和过去分词均表示必然结果：

He was late again and again， thus making the boss angry.

He smoked again at work， thus caught by the boss.

5.作补语

（1）作宾补或主补时，不定式的逻辑主语就是句子的宾语或者主语，有主动和被动之分。常用动词有：advise， allow， ask， beg， cause， consider， desire， encourage， expect， force， get， invite， oblige， order， permit， persuade， prefer， request， teach， tell， want， warn等：

Our school doesnt permit anyone to smoke in the school campus.（宾补）

We were forced to leave the classroom when school was over. （主补）

（2）动词notice， let， make， hear， listen to， see， look at， watch， observe， have， feel跟省略to的不定式作宾补，但这些动词变为被动语态时，作主补的不定式要加上to：

I noticed a young lady enter the room hurriedly.

A young lady was noticed to enter the room hurriedly.

6.作表语

不定式作表语既可表示将来发生的动作，也可表示应该做某事：

My job is to teach children English after graduation.

Who is to blame for the broken window？

二、动词不定式的时态和语态

不定式不仅有时态的变化，而且有语态的变化。当不定式的逻辑主语是不定式动作的承受者时，就用被动语态。

1.一般式表示动作或状态与谓语动词动作或状态同时发生或之后发生：

He likes to swim in the small river this afternoon.

Nobody likes to be criticized in public.

2.完成式表示动作或状态在谓语动词动作或状态之前发生：

He was lucky to have met a kind and helpful man.

The book is said to have been translated into English.

3.进行式表示动作在谓语动词动作或状态发生时正在发生：

He pretended to be sleeping when his mother told him to do washing.

4.完成进行式表示在谓语动词动作或状态发生之前开始的动作，到谓语动词动作发生时可能停止，也可能会持续下去：

He seems to have been standing there for five hours.

三、动词不定式的否定及其它

1.不定式的否定式是在不定式符号to前面加not：

The teacher ordered us not to make any noise in the classroom.

2.疑问词+不定式

“疑问词+不定式”相当于一个名词，在句中作主语、宾语和表语，其中的不定式常用一般式：

When to start for the journey has not been decided.

If you dont know when to start for the journey， youd better call him.

The problem is when to start for the journey.

3.不定式to的省略情况

（1）在had better， would rather…than…， would…rather than…， do nothing but ＼ except ＼ other than， might as well， cannot help but ＼ cannot choose but ＼ cannot but以及情态动词、助动词之后：

I would rather stay at home than go to the cinema in such terrible weather.

There is nothing I can do other than ＼ but ＼ except ask for a leave.

（2）动词help后可直接跟省略to的不定式，即help do sth.；help后的不定式作宾补时，如果句子主语直接参与不定式动作时省略to，句子主语不直接参与不定式动作时，一般不省略to：

Please help do housework， as I am too busy.

Would you please help me carry the box upstairs？

The book will help me to improve my writing skills.

（3）在why 或why not开头、表示建议的疑问句中：

Why argue with your mother？

Why not go outside and breathe some fresh air？

（4）并列的两个以上的不定式，从第二个开始省略to，但对比关系中不能省略：

She will come to help us and give us a lecture.

We havent decided whether to go to America or to stay in China during the vacation.

（5）不定式作表语时，系动词前边有动词do的任何形式；句子主语是all或what引导的从句；主语被only， first， one， least及形容词最高级所修饰时：

The first thing I want to do now is （to） thank all the people who have helped me in my life.

All I can do is （to） offer him some money to buy food and clothes.

What she really hopes is （to） marry an honest man.

The only thing he can do is （to） do well in the exam.

参考文献：

[1]薄冰英语语法.开明出版社.

[2]张道真实用英语语法.外语教学与研究出版社.