动词不定式是一种非谓语动词形式,其结构为“to+动词原形”,其中to是其符号,它没有人称和数的变化。动词不定式在句子中可以用作主语、表语、宾语、补足语、定语、状语等。
作主语:
To be a doctor is hard. 做医生很难。
To learn English well is not easy. 学好英语不容易。
To say is to believe.眼见为实。
动词不定式(短语)作主语时,为了避免句子的头重脚轻,可以用“it”作形式主语,而把真正的主语--动词不定式(短语)放在句子的后部。
上面的句子可以改为:
It is hard to be a doctor.
It is not easy to learn English well.
It’s important to plant trees in spring.
如果动词不定式的动作是谁做的,可以在动词不定式前面加一个由介词for引导的短语,称为不定式的复合结构。
It’s good for us to read English aloud in the morning. 对我们来说每天早晨大声读英语是很有益的。
It is important for students to use English every day. 对学生来说每天使用英语是很重要的。
作表语:
在形式上,位于系动词后的就是表语。从含义上讲,表语是回答主语“是什么”或“怎么样”的语法成分。动词不定式(短语)作表语常用于系词be的后面。
His work is to drive a car. 他的工作是开车。
My job is to feed animals. 我的工作是饲养动物。
Her ambition is to be a doctor. 她的理想是当医生。
作宾语:
动词不定式(短语)可以放在一些动词后面用作宾语,能以动词不定式作宾语的动词有:begin, start, want, forget, remember, show, learn, like, hate, love, ask等。
I want to tell you a story. 我想给你讲个故事。
They begin to work at eight every morning. 他们每天早晨8点开始工作。
Don’t forget to lock the door.别忘了锁门。
Would you like to go and have a picnic with us tomorrow?明天和我们起去野餐好吗?
【特殊】
1.如果and连接两个动词不定式,第二个动词不定式一般省“to”。
He wants to go and have a swim with us. 他想和我们一起去游泳。
2.若作宾语的动词不定式(短语)很长,可用it作形式宾语。
I find it interesting to learn English with you. 我觉得和你一起学英语很有趣。
He found it hard to catch up with others.他觉得赶上别人很困难。
作宾语补足语:
The teacher asked us to read English for half an hour in the morning.老师让我们早晨读半小时英语。
The teacher often tells Jim not to spend too much time playing computer games.老师常告诉Jim不要花太多时间玩电脑游戏。
Please let me help you.让我来帮助你。
动词不定式作宾语补足语,表示宾语所做的动作,可以用动词不定式作宾语补足语的动词有:tell, ask, want, like, invite, encourage, help等。但在let, make, see, watch, hear, feel, notice, have等感官听觉动词或使役动词后面作宾语补足语的动词不定式一般要省略动词不定式符号“to”,可以归纳为以下三种句式:
不可以省to的不定式作宾语补足语:tell /ask / want / would like / wish / like / invite /encourage /teach sb. to do sth.
The teacher told us to come earlier tomorrow.
I want you to go now. 我想让你现在就走。
Her parents wish her to be a teacher.她父母亲希望她当老师。
省“to”的不定式作宾语补足语:Let / make / have sb. do sth.
Let the boy go out now. 让那个男孩出去。
The boy made the baby cry. 男孩弄哭了这个小孩。
see / watch / hear / notice / feel sb. do sth.
I saw the students play basketball on the playground yesterday.昨天我看见学生们在操场打篮球。
I often hear the girl sing in the next room. 我经常听到女孩在隔壁唱歌。
可省可不省的:help sb. (to)do sth.
I often help my mother (to)do housework. 我经常帮妈妈做家务。
(1)动词不定式的否定式是直接在to之前加not。
Tell them not to play football in the street.告诉他们不要在街道上踢足球。
(2)省to的动词不定式的否定式是直接在动词前面加not。
Let the boy not go. 让那个男孩别走。
(3)如果将主动语态变为被动语态时,作宾语补足语的动词不定式变为主语补足语,动词不定式则不省“to”,即原来省的再加上。
The boy made the baby cry.
·The baby was made to cry by the boy.那个孩子被男孩弄哭了。
作定语:
动词不定式作定语常用来修饰名词或不定代词,放于所修饰的词后,为后置定语。
Who was the first one to arrive? 谁第一个到的?
She has no paper to write on? 她没有纸写字?
The best way to learn English is to use it. 学英语最好的方法是使用它。
When is the best time to plant vegetables?什么时候是种植蔬菜的最好时间? · Do you have something to drink? 你这有喝的吗?
动词不定式(短语)作定语修饰名词时,与其所修饰的词具有一种动宾关系,如果不定式中的动词为不及物动词时,其后应加上一个含义上所需要的介词。
I have no chair to sit on.我没有椅子坐。
He has no house to live in.他没有房子住。
作目的状语:
动词不定式作目的状语常用在go, come, hurry等不及物动词后,表目的。
He went to see his sister yesterday.他昨天去看妹妹了。
They got up early to catch the early bus.他们早起去赶早班车。
有时可以把不定式(短语)提前,放于句首,表示强调目的。
To learn English quickly and well, he went to England.为了更快更好地学英语,他去了英国。
动词不定式考点解析:
一、动词不定式作主语
1. It's our duty _________ the room every day.
A. to clean
B. cleaned
C. clean
D. cleans (甘肃省)
2. It's hard for us _________ English well.
A. learn
B. learns
C. to learn
D. learning (江西省)
3. 建造这座立交桥将花费工人们一年多的时间。
It will _________ the workers over a year _________ _________ the flyover.(北京市海淀区)
4. It's very nice _________ you to get me two tickets _________ the World Cup.
A. for, of
B. of, for
C. to, for
D. of, to (安徽省)
Keys: 1. A 2. C 3. take,to, build 4. B
[解析]动词不定式作主语时,可以直接放在谓语动词前面的主语位置,也可以用先行词it作形式主语,而将真正的主语(不定式)置于后面。常见的句式有:(1)It is +形容词(of sb)to do sth.(2)It is +名词(for sb)to do sth.(3)It takes sb some time to do sth.(4)It is +形容词(for sb)to do sth.句式(1)中常用nice, kind, clever, good, right, wrong, foolish, careless等形容词,与介词of搭配,这些形容词常表述不定式逻辑主语的属性或性质;句式(4)中常用hard, difficult, easy, important等形容词,与介词for搭配,表示不定式表示的动作、行为的性质。
二、动词不定式作宾语
1. He wants ______ some vegetables.
A. buy
B. buying
C. to buy
D. buys (山西省)
2. Don't forget ______ your homework with you when you come to school.
A. to bring
B. bringing
C. to take
D. taking (福建省)
3. He found it very difficult ______.
A. sleeping
B. sleeps
C. slept
D. to fall asleep (湖南省)
Keys: 1. C 2. A 3. D
[解析]在want, like, agree, hope, wish, learn, begin, start, seem, decide, hate, choose, forget, remember等动词后面,可以接不定式作宾语。如果其后接形容词补足语时,则可以用it作形式宾语,而把作真正宾语的不定式放到后面。
◆◆顺口溜总结◆◆
★V.+to do结构的动词:
三个“希望”两“答应”
两个“要求”莫“拒绝”
“设法”“学会”做“决定”
不要“假装”在“选择”
“迫不及待”想记住
★省to不定式作宾补顺口溜:
省to宾补有十一,五看二听三使役;
一个帮助两均可,还有一个是感觉。
如若主动变被动,小to一定要带齐。
即:在have, let, make使役动词;notice, observe, see, watch, look at, hear, listen to, feel, help等感观动词 + sb. do sth.
动词不定式的省略:
1、在 be + 形容词 (如:glad, happy, pleased, anxious, willing, ready等词后保留 to.
1)-- Will you join us in a talk?
-- Yes, I’ll be glad to.
不定保留 to, 常见形容词;
愿意三高兴, 一个备着急。
2、在 love, like, mean, hope, advise, expect, want, persuade, refuse, wish, seem等动词后保留 to.
1)-- Would you like some bananas?
-- Yes, I’d love to.
动后保留to, 有爱莫拒绝;
愿喜似期希,想劝提建议。
3、在 have, need, ought, be able, be going, used等动词后保留 to.
1)I didn’t want to go there, but I had to.
2) We get on pretty well. Better than we used to.
情态常带 to,过去不得不;
需要是另类,应将能力住。
4、在 ask / tell / advise / persuade / wish / permit / allow + sb + to do sth结构中保留 to.
1)Don’t touch anything unless your teacher tells you to.
动后带 to作宾补,请叫建议和告诉;
但愿也留两允许, 勿忘一个要劝服。
形式宾语的介绍:
不定式出现在find, think后,作宾语时,常用it代替,而将真正的宾语放在后面。
如: I find it easy to read English every day.
常见的一些不带to的动词不定式Why not do..., Why don't you do..., had better(not)do..., would rather do, could/would/will you please(not)do...
如: I would rather stay in the room.我宁愿待在房间里。
3. 不定式做表语
表语也就是句子的第③号位置
翻译这个句子:
我的梦想是去做一名医生。
My dream is to be a doctor.
③
我喜欢打篮球。
I like to play basketball.
③
出现在句子的第三位,做表语,对主语进行表示说明。
4. 不定式做补语
翻译这个句子:
妈妈让我一直弹钢琴。
My mom made me play piano all the time.
④
可以看见这个不定式的位置,出现在句子的第④位,对宾语me进行补充说明。
注意:在make,let,see,hear,watch等使役、感官动词后,不定式省略to,也就是只剩下一个动词原形。
5. 不定式做定语
翻译这个句子:
你有什么事情要说吗?
Do you have anything to say?
To say出现在不定代词的后面,修饰这个代词,起到定语的作用,由于字数超过2个,所以要放在代词的后面。
我们看看另一种情况:
翻译:没有什么可担心的。
There is nothing to worry about.
此处worry是不及物动词,要添加介词about。
6. 不定式做状语
翻译这个句子:
很抱歉,给你添麻烦了。
I'm sorry to bother you.(表原因)(八年级下册考点)
我来图书馆为了学英语。
I went to the library to study English.(表目的)
7. 不定式的特殊用法
不定式常和疑问词what, which, when, where, how连用,相当于一个宾语从句(八年级考点)。如:
老师正告诉学生们做什么。
The teacher is telling the students what to do.
他不知道去哪里。
He didn't know where to go.
动词不定式专题训练(单项选择):
1. Reading provides me with fun and it also enables me ______ the world around me.
A. understand B. understood C.to understand D. understanding
2. My work is ______ the room every day.
A. clean B. to clean C. cleaning D. cleans
3. Since the river is seriously polluted, I have warned Jack _____ in it.
A. not to swim B. to not swim C. swim not to D. to swim not
4. It was silly of you ______ him.
A. believe B. to believe C. believing D. believes
5. The best way ______ your English is to join an English club.
A. improves B. improved C. to improve D. improving
6. The chair looks rather hard, but in fact it is comfortable ________.
A. to sit B. to sit on C. sitting D. sat on
7. We saw him _______ the building and go upstairs.
A. to enter B. enter C. entering D. entered
8. So much work usually makes them ______ very tired.
A. to feel B. feels C. feeling D. feel
9. The woman feels that she should let her son ______ his own decision this time.
A. makes B.make C. to make D. making
10. You’d better ______because you have to drive back home.
A. not drinking B. not drink C. don’t drink D. not to drink
11. –How about going hiking this weekend?
--Sorry, I would rather ______.
C. staying at home D. stayed at hom
A. to stay at home B. stay at home
12. On the way home, Lucy saw a thief________ in a shop. She stopped_____ 110 at once.
A. steal, call B. to steal, call C. stealing, to call D. stealing, calling
答案:1. C 2.B 3.A 4.B 5.C 6.B 7.B 8.D 9.B 10.B 11.B 12.C
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