英語動詞不定式用法詳解

楊正仁

【摘要】非謂語動詞是由動詞變來但不能作謂語的一種形式，但可以帶自己的賓語或狀語，構成非謂語動詞短語。非謂語動詞之不定式在句中作主語、賓語、定語、狀語、補語和表語，同時動詞不定式也有時態(tài)、語態(tài)和否定形式。

【關鍵詞】動詞不定式 句法功能 時態(tài)語態(tài) 否定式 疑問詞+不定式 省略

非謂語動詞是由動詞變來但不能作謂語的動詞形式，但可以帶自己的賓語或狀語，構成非謂語動詞短語。不定式是最常用的非謂語動詞之一，下面從句法功能、時態(tài)和語態(tài)等方面舉例說明其用法。

一、句法功能

動詞不定式具有名詞、形容詞和副詞之特性，同時也保留動詞特征，同自己的賓語和狀語一起構成不定式短語，在句中作主語、賓語、定語、狀語、補語、表語。

1.作主語

To love and to be loved are both happiness.

（1）不定式作主語時，為了避免頭重腳輕，常用it作形式主語，不定式作真正主語，常見句型有：

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）不定式的邏輯主語用of或for引出。用for時，它前面的形容詞說明不定式的性質，而不是說明邏輯主語，常見的形容詞有：important， necessary， difficult等；用of時，常用表示人的品質的形容詞，常見形容詞有：nice， good， cruel， typical， silly， foolish， stupid， bright， clever， wise， right， wrong， mistaken等，也可以用“邏輯主語+系動詞+該形容詞”模式改寫：

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.作賓語

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

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等動詞后跟不定式和動名詞作賓語意義接近，區(qū)別在于不定式表示具體的動作，動名詞表示抽象概念：

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

（3）不定式作賓語時，用it作形式賓語，常跟一個形容詞或者名詞作賓補：

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.作定語

（1）作定語時，與被修飾詞之間有邏輯上的“主謂關系”、“動賓關系”等：

He is always the first to come and the last to go. （主謂關系）

I have a very important meeting to attend this afternoon. （動賓關系）

I will go to Shanghai. Do you have anything to be taken there？ （主謂關系）

注：此句中you不是不定式邏輯主語，故anything就成邏輯主語，anything與take之前構成被動關系，故用被動形式，但也可用主動形式：

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）如果作定語的動詞不能與被修飾詞之間構成動賓關系時，要加相應的介詞，構成介賓關系：

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

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

The girl has the ability to operate this modern machine.

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

4.作狀語

不定式作狀語時，通常表示原因、目的和結果，邏輯主語通是句子的主語，有主動和被動之分：

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：不定式在這種情況下作狀語，一般是及物動詞，與主語之間是邏輯上的動賓關系，翻譯為“…起來”，不用被動式：

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.（結果）

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

注意：分詞也可作結果狀語，但不定式的主動和被動形式都表示出乎預料的結果，而現(xiàn)在分詞和過去分詞均表示必然結果：

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

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

5.作補語

（1）作賓補或主補時，不定式的邏輯主語就是句子的賓語或者主語，有主動和被動之分。常用動詞有：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.（賓補）

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

（2）動詞notice， let， make， hear， listen to， see， look at， watch， observe， have， feel跟省略to的不定式作賓補，但這些動詞變?yōu)楸粍诱Z態(tài)時，作主補的不定式要加上to：

I noticed a young lady enter the room hurriedly.

A young lady was noticed to enter the room hurriedly.

6.作表語

不定式作表語既可表示將來發(fā)生的動作，也可表示應該做某事：

My job is to teach children English after graduation.

Who is to blame for the broken window？

二、動詞不定式的時態(tài)和語態(tài)

不定式不僅有時態(tài)的變化，而且有語態(tài)的變化。當不定式的邏輯主語是不定式動作的承受者時，就用被動語態(tài)。

1.一般式表示動作或狀態(tài)與謂語動詞動作或狀態(tài)同時發(fā)生或之后發(fā)生：

He likes to swim in the small river this afternoon.

Nobody likes to be criticized in public.

2.完成式表示動作或狀態(tài)在謂語動詞動作或狀態(tài)之前發(fā)生：

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

The book is said to have been translated into English.

3.進行式表示動作在謂語動詞動作或狀態(tài)發(fā)生時正在發(fā)生：

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

4.完成進行式表示在謂語動詞動作或狀態(tài)發(fā)生之前開始的動作，到謂語動詞動作發(fā)生時可能停止，也可能會持續(xù)下去：

He seems to have been standing there for five hours.

三、動詞不定式的否定及其它

1.不定式的否定式是在不定式符號to前面加not：

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

2.疑問詞+不定式

“疑問詞+不定式”相當于一個名詞，在句中作主語、賓語和表語，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的省略情況

（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以及情態(tài)動詞、助動詞之后：

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）動詞help后可直接跟省略to的不定式，即help do sth.；help后的不定式作賓補時，如果句子主語直接參與不定式動作時省略to，句子主語不直接參與不定式動作時，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開頭、表示建議的疑問句中：

Why argue with your mother？

Why not go outside and breathe some fresh air？

（4）并列的兩個以上的不定式，從第二個開始省略to，但對比關系中不能省略：

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）不定式作表語時，系動詞前邊有動詞do的任何形式；句子主語是all或what引導的從句；主語被only， first， one， least及形容詞最高級所修飾時：

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.

參考文獻：

[1]薄冰英語語法.開明出版社.

[2]張道真實用英語語法.外語教學與研究出版社.