高中英语语法讲解不定式
高中英语语法讲解不定式
(The Infin itive )
定义：动词不定式是非谓语动词的一种，它没有人称和数的变化，在句子中不能独立作谓语，
但它仍保持动词的特点，既可以有自己的宾语和状语。 E.g. He want his students to read the book aloud.
A.
1
2
不定式的一般式(to do )
一般式表示的动作或状态，发生在谓语动词表示的动作或状态的同时或之后
My wish is to become a doctor
He seemed to be tired.
She stopped to have a rest.
不定式的被动式(to be don e)
当不定式的逻辑主语是这个不定式所表示的动作的承受者时，不定式一般要用被动式.
The build ing to be fini shed n ext mo nth is for our teachers.
I am going to Beijing, I have something to take to my parents, do you have something
to be take n to your pare nts?
如果谓语表示的动作(情况)发生时，不定式表示动作正在进行,这时候不定式就要用进行式. (to be doing )
They are said to be buildi ng ano ther bridge across the street.
They seemed to be talki ng about someth ing importa nt.
When I went to his home, he happe ned to be traveli ng around the world.
I ' m glad to be working with you.
如果不定式所表示的动作或状态发生在谓语动词所表示动作或状态之前，就用完成式(to have
done);若是在此基础上的被动含义，就用完成被动式(to have been done).
He is said to have written a novel about the Long March.
He thought it a pity not to have in vited us.
The assista nt seemed to have bee n fired.
He is said to have bee n taught French whe n he was a child.
Ein ste in is said to have built up his theory whe n he was in his twen ties.
如果不定式的动作是在谓语所表示的时间之前一直在进行的动作，就要用完成进行式They are said to have bee n collecti ng folk song in Xinjia ng.
We re happy to have bee n worki ng with the experts all the mon th.
B.用法：
动词不定式具有名词、形容词和副词的特征。因此在句中可以做主语、表语、宾语、宾语补足语、定语和状语。
一、不定式做主语：
1、不定式做主语一般表示具体的某次动作。===动名词doing表示习惯的，经常的动作。
e.g: To finish the build ing in a month is difficult.
To do such things is foolish.
To see is to believe.( 对等)
注:1). 不定式作主语时，谓语用单数
2) .当主语较长，谓语较短时，常用it做形式主语，而将不定式放到谓语的后面。
it做形式主语，不定式放在谓语动词之后常用于下列结构中：
(1) lt is/was +adj.+of sb. to do …
(2) It is +adj.+for sb.+to do …
It is easy / difficult / hard / foolish / un wise / right / wrong / unn ecessary
⑶ it is +a + 名词+ to do...
It is a pity / a pleasure / a pleasant thing / one ' s duty / an honor / a shame
/ a crime / no easy job …to do
It takes (sb.) some time / courage / patienee …to do …
It requires courage / patienee / hard work …to do …
*注意：probable 和possible 均可作表语，但possible 可以用不定式作真实主语，而probable不能用不定式作真实主语。
It is probable for him to come to the meeti ng.( 错)
It is possible for him to come to the meet ing.
It is possible / probable that he will come to the meet ing.
二、不定式做表语
主语是以aim duty hope idea intention plan job suggestion wish purpose
task等为中心词的名词词组或以what引导的名词性从句表示，后面的不定式说明其内容，不定式作表语常表示将来或现在的动作或状态。
eg My idea is to climb the mountain from the n orth.
Your mistake was not to write that letter.
What I would suggest is to start work at on ce.
三动词不定式作宾语
以不定式结构为宾语的动词有：
ask, agree, care, choose, dema nd, decide, expect, fail, help, hope, lear n, man age, offer, pla n, prepare, prete nd, promise, refuse, want, wish 等只能用动词不定式作宾语
口诀(接不定式作宾语的动词)
想要学习早打算(want learn plan )
快准备有希望(prepare hope wish expect )
同意否供选择(agree offer choose )
决定了已答应(decide be determined promise )
尽力去着手做(man age un dertake )
别拒绝别假装(refuse pretend )
失败不是属于你(fail )
e.g.Tom refused to lend me his pen.
We hope to get there before dark.
The girl decided to do it herself.
* 注意: 某些及物动词可用-ing 也可用动词不定式作宾语但意义不同的有stop go on remember forget regret try mean can' t help
be used to
四．动词不定式做定语
1．. 不定式作定语需要后置。
2. 作定语的不定式与被修饰的名词或代词存在着两种主要的逻辑关系，即被修饰的名词和代词是不定式的逻辑主语（逻辑上的主谓关系）或逻辑宾语（逻辑上的动宾关系）
1）不定式前的名词是它的逻辑主语。
He is the doctor to do the operation.
2）不定式和它所修饰的名词是逻辑上的动宾关系。
I have a lot of things to do.
3）不定式前的名词是它修饰的对象。
This is the right time to start.
注意．如果不定式所修饰的词是way 或place, 介词可省略。
He has no way to go （by）. This is the best place to work （at）
五．宾语补足语
He want you to be his assistant. I saw her cross the street.
[ 注1] 如果谓语动词为感官动词或使役动词，则作宾补的不定式不可带to ，这些动词有see, hear, feel, watch, notice; have, make, let 等。
I felt my blood run cold. What made you think like that? 但如果句子是被动语态，则to 不可省略。
He was made to clean the windows as a punishment.
Someone was heard to come up the stairs.
[ 注2] 1. 谓语动词help 后可接带to 或不带to 的不定式作宾补。用不带to 的不定式表示帮助者直接参与动作；用带to 的不定式表示主语没有直接参与动作。
They helped me carry the boxes.
This kind of soap will help you to wash the clothes more easily.
2. 在美式英语或非正式文体中，help 后用作宾补的不定式均不带to 。
3. help 后可以直接用带to 或不带to 的不定式作宾语。
They helped （to） carry the furniture upstairs.
[ 注3]look at 及listen to 后用作宾补的不定式不带to （这主要是美式英语）。
We have been listening to the radio tell a long story.
六．表语补足语当不定式与主语存在逻辑上动宾关系的时候，用主动表被动。
That is hard to say. The chair is comfortable to sit in.
七．不定式做状语不定式做状语修饰动词、形容词、副词等，表示目的、原因、结果、条件等。
1、表目的
e.g. To learn a foreign language well, you must try your best （主语一致） He came here to attend an important meeting.
He came here in order to see Charlie.
I turned the radio down so as not to disturb him
注：表示目的的不定式可以置于句首，这也是区别于其他功能的标志之一。
*但是，置于句首表示目的的不定式可以是to, in order to ，但却不可以是so as to. ” , ”
To draw maps properly, you n eed a special pen.
In order to draw maps properly, you n eed a special pen.
To get the best results, use clea n water.
To be elected mon itor of our class, he gave money to us.
*放在句末时，to do 表示目的，不可有“，”若有用doing表示伴随的目的
e.g. He bowed to us to tha nk us for help ing him find the way.
He worked day and ni ght, hop ing to finish the work beforeha nd.
注：1.不定式结构表示目的时，通常句子的主语就是它的逻辑主语(主语一致)
e.g.He bought a bicycle to go to tow n more quickly.
He went home to see his mother.
例夕卜 e g He opened the door for the children to come in.
They sent a man to mend the wi ndow.
2、表结果
不定式结构表示结果更常见于下列句型
①so…as to …
Would you be so kind as to lend me your bicycle / tell me the time?
②such (…)as to …
I ' m not such a fool as to believe th at.
③adj./adv. + eno ugh to …
The boy is old eno ugh to go to school.
④too…to …
His eyesight is too poor to read such small letters.
(5) only to find , only to be told 出乎意料之外的结果
3. 原因不定式可以用于动词、形容词或-ed分词后表示原因。
He was too excited to get high marks.
八.同位语
Is this your purpose, to avoid being puni shed?
九.独立成分
To tell you the truth, I don ' t like you. They arrived here at 11:55 a.m., to be exact.
类似的有：to be fra nk 坦率地说，to hear him talk 听他说话的口气，to cut a long
story short 长话短说，等等。
C
不定式的各种结构
1 .宾格词+不定式
1 )普通结构此结构中的宾格词为名词或代词的宾格，宾格词是谓语动词的宾语，同时
又是不定式的逻辑主语，不定式和宾格词一起构成复合宾语。
I want Henry to come. She expects this to be true. I heard them sing yesterday.
2) “ there to be + 宾格词”结构
此结构的宾格词仍是不定式的逻辑主语，只是它位于不定式to be的后面。
I don ' t want there to be any misunderstanding.
3) 各种形式的不定式都可以用于此种结构中。
The judge wan ted the man to be puni shed.
He expected each of his stude nts to be worki ng hard for the coming exam.
2 .主格词+不定式
当上一种结构变为被动语态时，就出现了此种结构，此结构中，不定式都要带to 词是不定式的逻辑主语，不定式在句中作主语补足语。
They are allowed to go. J We allowed them to go.
He was see n to en ter the store. J I saw him en ter the store.
3 . for + 宾格词+不定式
此结构中，宾格词是不定式的逻辑主语，这种结构在句中可作：
1) 主语It is difficult for us to learn a second foreign Ianguage.
2 ) 宾语I con sider it n ecessary for her to lear n Fren ch.
3 ) 表语The best thing is for us to make our own decisi on.
4) 定语There is a lot of work for us to do.
5) 状语He ope ned the door for the car to en ter.
The book is too easy for them to read.
4 . with/without + 宾格词+ 不定式
此结构在句中常作原因状语，宾格词是不定式的逻辑宾语。
With so much work to do, I shall not be able to watch the match with you.
Without anything to eat, he died of hun ger.
5 ?疑问词+不定式此结构相当于名词词组，在句中可作：
1) 主语When to visit that farm has not been decided yet.
2) 宾语We must know how to operate this mach ine.
3) 表语The problem now is how to collect eno ugh mon ey.
4) 同位语The problem what to do next is unknown.
注意intend, plan, hope, expect, mean, promise, want, think, wish, were (was),
like, should like + 不定式完成式，可表过去没有实现的愿望，期待和计划。
He intended to h ave come. = He intended to come, but he didn ' t.
She wished to have bought a car. = She wished to buy a car, but she didn ' t.
I meant to have called on you, but I was too busy.
She hoped to have passed the exam. (but she didn ' t)
I would like to have go ne abroad. (but I didn ' t)
D
不定式的否定式
通常是在不定式前加not，表示较强的否定意义时可用never。
I told him not to touch the equipment. You must promise never to do that
E特殊动词不定式的“省略与保留”
一、不定式符号的省略与保留
1. 在had better, would rather, would rather...than, would sooner...than,
cannot but, why (not) 等结构后面的不定式符号to通常被省略。如：
You' d better tell her the truth. 你最好告诉她真相。
2. 动词不定式短语作介词but, except, besides的宾语，且介词之前有行为动词
它的其它形式时，不定式符号to通常被省略。如：
What do you like to do besides swim?
除了游泳，你还喜欢干什么？
My mother could do nothing but wait for the doctor to arrive.
妈妈只好等着医生的到来。，主格would
aga in. do或
Now he had given himself no choice but to tell her. （本句中不定式符号to 不可省略）
当时他毫无选择的余地, 只好告诉她了。
3. 两个或多个不定式短语表示并列关系时, 后面不定式短语的不定式符号to 通常被省略; 如果表示对比关系, 则不定式中的不定式符号to 通常要保留。如:
They didn ' t tell me whether to go on or to stop.（对比关系）
他们没有告诉我是继续下去还是停止。
She told the child to stay there and wait till she came back.（并列关系）她让孩子待在那里等
她回来。
4. 在某些感官动词或使役动词（如hear, listen to, notice, observe, see, watch,
make等）之后充当宾语补足语的不定式中,不定式符号to总是被省略，但在被动语态的句子中,
不定式符号to 通常要保留。如:
They made that man work all the morning.
他们让那个人干了一个早晨。
That man was made to work all the morning.
那个人被要求干了一个早晨。
5. 不定式短语作表语，不定式符号to 常常要保留，但当what 引导的名词性从句作主语，或all， everything 等后接定语从句作主语，从句谓语部分含有动词do 或do 的其他形式时，作表语的不定式可以保留也可省略不定式符号to 。如:
The greatest happiness is to work for the happiness of all. 最大的幸福就是为大家的幸福而工作。
The only thing I can do now is （to）go on by myself.
我现在唯一能做的就是靠自己继续进行下去。
二、不定式符号后面动词的省略与保留
1. 为了避免重复，在hope， wish， want， like， love， decide， plan， mean，
prefer，
want， have to， be able to， be going to， used to， ought to 等动词及习语后面出现与上
文相同的不定式时，常保留不定式符号to，而把其它部分省略。如:
Ms King lied to us because she had to.
金女士跟我们撒了谎，因为她不得不这样做。
－I heard that you would go to Dalian for your holiday. 我听说你要去大连度假。
－I planned to， but I have some important business to deal with. 我原计划去的，但有重要的事情要处理。
2. 当不定式在ask， advise， persuade， wish， allow， permit， tell， expect， force，invite， beg 等动词后面充当宾语补足语时，为了避免重复，常保留不定式符号，而把后面的动词
省略。如:
She wants to co me but her parents won 't allow her to.
她想来，但她的父母不允许。
If he doesn 't want to go there， don 't force him to.
如果他不想去那里，别强迫他。
He didn 't come， though we had invited him to.
虽然我们邀请了他，但他没来。
－Did your husband give up smoking?
你丈夫戒烟了吗?
－No. He was advised to， but he wouldn 't listen.
没有。有人劝过他，但他就是不听。
3. 在特定的上下文中，为了避免重复，如果不定式为一般式to be... 或完成式to have
done 时，则不定式符号to 和be 或have 常一并保留，be 或have 之后的部分通常要省略。如: －Aren't you the headmaster?
你难道不是校长吗?
－No， and I don 't want to be.