初中英语动词不定式精讲精练.doc

动词不定式
　　动词不定式是动词的一种非谓语形式，没有人称和数的变化，不能单独作句子的谓语。其构成形式为"to+动词原形"，to为动词不定式的符号，本身无意义。动词不定式具有两大特点：
　　1.具有动词的特点，因此，后面可以跟表语、宾语或状语，构成动词不定式短语。
　　2.具有名词、形容词或副词的特点，可以在句子中用作主语、宾语、宾语补足语、状语、定语、表语及同位语等
1.作主语
动词不定式作主语时，句子的谓语动词常用单数，其位置有以下两种：
(1)把不定式置于句首。如：
To get there by bike will take us half an hour.
骑自行车到那儿将花费我们半个小时。
To make up for lost time is not possible.
要弥补失去的时光是不可能的。
To lean out of the window is dangerous.
身子探出窗外很危险。
To save money now seems impossible.
现在好像不可能存钱。
(2)用it作形式主语，把真正的主语不定式置于句后，常用于下列句式中。如：
①It+be+名词+to do
It's our duty to take good care of the old.
这是照顾老人是我们的责任。
②It takes sb+some time+to do
How long did it take you to finish the work?
你花了多少时间来完成这项工作吗？
③It+be+形容词+for sb+to do
It is difficult for us to finish writing the composition in a quarter of an hour.
我们难以在四分之一小时内完成这篇作文。
It is stupid of you to write down everything (that) the teacher says.
It is an offence to drop litter in the street.
在马路上乱丢废物是违章的。
④It seems(appears)+形容词+to do
It seemed impossible to save money.
在句型③中，常用表示客观情况的形容词，如：difficult,easy,hard,important,impossible,necessary 等；在句型④中，常用careless,clever,good,foolish,honest,kind,lazy,nice,right,silly,stupid,wise等 表示赞扬或批评的词。在不定式前的sb，可看作其逻辑主语。这一句式有时相当于Sb is+形容词+to do句式 ，如：It's kind of you to help me with my English.=You are kind to help me with my English.
⑤It + 不定式结构可位于believe/consider/discover/expect/find/think和wonder之后
He thought it would be safer to go by train.
他认为乘火车比较安全。
He will find it is hard to make friends.
他会感觉到交朋友困难。
⑥不定式的完成式也可作句子的主语
To have made the same mistake twice was unforgivable.
两次犯同样的错误是不可原谅的。
It is better to have loved and lost than never to have loved at all.
爱过而后失去了爱，比从未爱过要好。
(3)举例
（1） It's easy (for me) to do that.我做这事太容易了
easy,　difficult,　hard,　important,　possible,　impossible,　comfortable,　necessary,　better;
the first,　the next,　the last,　the best,　too much,　too little,　not enough
It's so nice to hear your voice.
听到你的声音真高兴。
It's necessary for you to lock the car when you do not use it.
当你不用车的时候，锁车是有必要的。
（2） It's very kind of him to help us.　他帮助我们，他真好。
Kind,　nice,　stupid,　rude,　clever,　foolish,　thoughtful,　thoughtless,　brave,　considerate(考虑周到的),　silly,　selfish(自私的)
例句:
It was silly of us to believe him.　我们真愚蠢，竟然相信了他。
It seemed selfish of him not to give them anything.　他不给他们任何东西，这显得太自私了。
注意：（1） 其他系动词如，look，appear等也可用于此句型
（2） 不定式作为句子成分时，动词用单数形式。
（3） 当不定式作主语的句子中又有一个不定式作表语时，不能用It is… to…的句型
(对)To see is to believe.　眼见为实。
(错)It is to believe to see.
练习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)

3作宾语
1) 以下动词后，只能跟不定式作宾语
afford （付得起），agree（同意），aim(力求做到)，appear（显得），arrange（安排），ask（要求），attempt （试图），care（想要），choose（决定），claim（声称），condescend（屈尊），consent（准许），decide（决定），demand（要求），determine（决心），endeavor（竭力），expect（期待），fail（未履行），help（帮助），hesitate（犹豫），hope（希望），learn（学会），manage（设法），neglect（疏忽），offer（主动提出），plan（计划），prepare（准备），pretend（假装），proceed（接着做），promise（答应），prove（证明），refuse（拒绝），resolve（解决），seem（觉得好像），swear（发誓），tend（往往会），threaten（预示），undertake（承诺），volunteer（自愿做），vow（发誓），want（想要），wish（希望）
举例：
The driver failed to see the other car in time.
司机没能及时看见另一辆车。
I happen to know the answer to your question.
我碰巧知道你那道问题的答案。
2） 动词+疑问词+ 不定式
decide,know,consider forget,learn,remember,show,understand,see,wonder,hear,find out,explain,tell
Please show us how to do that. 请演示给我们如何去做。
There are so many kinds of tape-recorders on sale that I can't make up my mind which to buy.有这么多的录音机，我都拿不定主意买哪一种。
注意：疑问词带不定式在句中作成分时，谓语动词用单数。
The question is how to put it into practice.
问题是怎样把它付诸实施。
3)当复合宾语中的宾语是不定式时，先用形式宾语it代替不定式，把不定式置于补语之后，即：主语+动词+it+补语+to do句式。如：
We think it quite important for us to learn a foreign language well.
He feels it his duty to help the poor.
I find it difficult to learn English well.
练习：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. sleepsC. slept D. to fall asleep (湖南省)

4作补语
1) 动词+宾语+不定式(to do)
advise　allow　believe　cause　challenge　compel　declare　encourage　forbid　force　find　hire　induce instruct　invite　like　order　permit　persuade　remind　request　require　select　send　suppose　tell　train　urge
例句：
a.　Father will not allow us to play on the street.
父亲不让我们在街上玩耍。
b.　We believe him to be guilty.
我们相信他是有罪的。
练习1. Robert often asks us ______ his Chinese, so his Chinese is much better than before.
　　A. help him B. to help him with C. to help with D. helps him with (江苏省)
　　2. Mr Li often teaches his Japanese friends ______ Chinese food.
　　A. cook B. cooks C. to cook D. cooked (甘肃省)

5 Find 的特殊用法：
Find 后可用分词做宾补，或先加形式宾语，再加形容词，最后加带to 的动词不定式。find后也可带一个从句。此类动词还有get，have。
I found him lying on the ground.
I found it important to learn.
I found that to learn English is important.

6典型例题：
The next morning she found the man ___ in bed，dead.
A. lying　B. lie　C. lay　D. laying
答案：A.find的宾语后面，用分词或分词短语，起宾语补足语作用。现在分词表达主动，也表达正在进行，过去分词表达被动。
2) to + be 的不定式结构，作补语的动词。
Acknowledge,　believe,　consider,　think,　declare(声称),　discover, fancy(设想),　feel,　find,　guess,　judge,　imagine,　know,　prove,　see(理解), show,　suppose,　take(以为),　understand
We consider Tom to be one of the best students in our class.
我们认为汤姆是班上最好的学生之一。
7典型例题:
Charles Babbage is generally considered　___ the first computer.
A. to invent　B. inventing　C. to have invented　D. having invented
答案：A. 由consider to do sth. 排除B、D，此句只说明发明这一个事实，不定式后用原形即可。而C为现在完成时，发明为点动词一般不用完成时，且此处也不强调对现在的影响，因此不选C。
3) to be +形容词
Seem,　appear,　be said,　be supposed,　be believed,　be thought,　be known,　be reported,　hope, wish,　desire,　want,　plan,　expect,　mean…
The book is believed to be uninteresting.
人们认为这本书没什么意思。
4)　there be+不定式
believe,expect,intend,like,love,mean,prefer,want,wish,undrstand
We didn't expect there to be so many people there.我们没料到会有那么多人在哪里。
有些动词需用as 短语做补语，如regard,think believe,take,consider.
We regard Tom as our best teacher.　我们认为汤姆是我们最好的老师。
Mary took him as her father .　玛丽把他当作自己的父亲。
5)秃头不定式作补语
秃头不定式， 即不带“to”的不定式，其语法功能一般在句子中作宾语的补语（宾语补足语）。
用秃头不定式作宾语补足语的常用动词如下：
口诀：“五看、三使役“，“两听、一感”要记住，若是“宾补”变“主补”，主补“to”字不能无。动词let属例外，其宾补/主补“to”均无。说明：
五看-----see/watch/notice/observe/look at；三使役-----have/make/let；两听-----hear/listen to；一感-----feel。
例句：I often see him go to school on foot.(秃头不定式作宾语补足语) He is often seen to go to school on foot.(不定式作主语补足语，要带“to”) Let him try again.---- He is let try again.(let的主补与宾补均用秃头不定式)
练习：1. We saw him ______ the building and go upstairs.
A. to enter B. enter C. entering D. entered (河南省)
2. So much work usually makes them ______ very tired.
　　A. to feel B. feels C. feeling D. feel (吉林省)
　　3. Your father is sleeping. You'd better ______.
　　A. not wake up him B. not to wake up him
　　C. not wake him up D. not to wake him up (陕西省)
　　4. I was made ______ my homework in the afternoon.
　　A. do B. doing C. to do D. did (贵州省)

8作表语
不定式作表语表示具体动作或将来动作；动名词作表语表示抽象的一般行为。
①To be kind to the enemy is to be cruel to the people.
②My chief purpose is to point out the difficulties of the matter.
③What I would suggest is to put off the meeting.
当主语和表语都是不定式时，其含义一是条件，一是结果（例①）。当主语是aim,duty,hope,idea,mista ke,plan,purpose,suggestion等为中心词的名词词组（例②）时，或以what引导的名词性分句（例③），不定 式说明主语的内容。
④Our work is serving the people.
⑤What he likes is taking a walk after supper.
⑥The story told by Mr.Wang is interesting.
④⑤句动名词作表语，与主语部分可以转换，如Serving thepeople is our work,而⑥句中是现在分词作表语，说明主语的性质、状态，现在分词具有形容词的各种特征，另外，动名词作表语还应与进行时态区别开来。
9作状语
（1）目的状语
To… only to (仅仅为了),　in order to,　so as to,　so(such)… as to… (如此……以便……)
He ran so fast as to catch the first bus.　他飞快地跑以便赶上第一班车。
I come here only to say good-bye to you.　我来仅仅是向你告别。
（2）作结果状语，表事先没有预料到的，要放在句子后面。
What have I said to make you angry.
He searched the room only to find nothing.
（3)表原因
I'm glad to see you.
典型例题
The chair looks rather hard,but in fact it is very comfortable to ___.
A. sit　B. sit on　C. be seat　D. be sat on
答案：B.　如果不定式为不及物动词，其后应有必要的介词
。当动词与介词连用时，常位于“形容词+动词不定式”结构的末尾。
练习：1. She went ______ her teacher.
A. to see B. looks C. saw D. seeing (江西省)
2. Meimei likes English very much. She does her best ______ English well.
A. learn B. learning C. to learn D. learns (四川省)
3. I'm sorry ______ that.
A. hears B. hearing C. hear D. to hear (河北省)
4. I'm sorry ______ you.
A. trouble B. to trouble C. troubling D. troubled (吉林省)
5. My mother was very glad ______ her old friend.
A. to meet B. meet C. met D. meets (甘肃省)
6. The panda is so fat that it can't go through the hole.(改为意思相同的句子)
The hole ______ ______ ______ ______ such a fat panda to go through. (广东省)
7. The ice on the lake was so thin that people couldn't skate on it. (改为意思相同的句子)
　The ice on the lake wasn't ______ enough ______ people ______ ______ ______. (广东省)

10作定语
⒈不定式作定语
不定式在句中作定语，置于被修饰的名词或代词之后。如：
①The next train to arrive is from Washington.
②Do you have anything to be taken to your sister?
③Do you have anything to say on the question?
④Would you please give me some paper to write on?
⑤My wish to visit France has come true at last.
不定式短语作定语和被修饰词之间表示以下关系：
(1)表示将来的动作（例①）。
(2)与被修饰词之间有动宾关系，如是不及物动词，则需加介词（例④）。
(3)与被修饰词之间有动宾关系，同时与句中其它词之间又有逻辑上的主谓关系时，尽管有被动含义，却仍用主动语态（例③）；如只有动宾关系，而无逻辑上的主谓关系，则需用被动语态（例②）。
(4)不定式作定语时，一般可转换为定语从句，例①to arrive=that will arrive。
练习：1. Would you like something ______?
A. drink B. drinking C. to drink D. drinks (湖北省)
2. I have a lot of homework ______.
A. do B. doing C. did D. to do (河南省)
3. He is not an easy man ______.
A. get on B. to get on C. get on with D. to get on with (山东省)
区别联系
1 动名词与不定式的区别
动名词表达的是：状态，性质，心境，抽象，经常性，已发生的　
不定式表达的是：目的，结果，原因，具体，一次性，将发生的
2 接不定式或动名词，意义相同
3在下列情况下，一般要用不定式：
①hate,like,love前有would(should)时，如：I'd like to have a cup of coffee.
②当谓语动词begin,continue,start等是进行式时，如：The students are starting to work on the difficult maths problem.
③begin,continue,start与know,understand等状态动词连用时，如：I soon began to understand what was happening.
⒋advise,allow,encourage,forbid,permit等动词后接动名词作宾语，或带不定式作宾语补足语。如：
Our teachers don't permit our/us swimming in the lake.
Our teachers don't permit us to swim in the lake.
4 部分动词后接不定式或动名词时，意义差别较大，应根据句子语境选择使用。
①forget,remember,regret后接不定式，表示现在或未来的动作，接动名词表示动作已经发生。如：
Don't forget to post the letter for me.
Have you forgotten meeting her in Beijing Airport?
Remember to close the windows before you leave.
I remember writing him a letter a year ago.
We regret to tell you that all of you are not invited toattend the meeting.
They regretted ordering these books from abroad.

语义不同
1　stop to do（停止做某事）　 stop doing（停止正在做某事）
2 forget to do（忘记去做某事）　forget doing（忘记做了某事）
3　remember to do（记得要去做某事）　remember doing（记得做过某事）
4 regret to do（遗憾做某事）　 regret doing（遗憾做了某事）
5cease to do　cease doing
6 try to do（努力做某事）　 try doing（试着做某事）
7　go on to do（继续去做某事）　go on doing（继续做某事）
8 afraid to do（担心做某事）　afraid doing（担心正在做的事）
9　interested to do（对做某事感兴趣）　interested doing（对正在做的感兴趣）
10 mean to do（打算做某事）　mean doing（做某事很有意义）
11 begin/ start to do（开始去做某事）　begin/ start doing（开始做某事）

1. Please stop ______ a rest if you feel tired.
　　A. to have B. having C. have D. has (广西壮族自治区)
　　2. ——Why didn't you buy some bread on your way home?
　　——Sorry, I forgot ______ some money with me.
　　A. take B. taking C. to take D. took (湖北省)
　　3. ——Let's have a rest, shall we?
　　——Not now, I can't stop ______ the letters.
　　A. write B. to write C. writing D. and write (湖北省)
4. Jim was badly hurt, so he had to stop ______ (walk). (用所给单词的正确形式填空)(四川省)

基础练习题
1. Don't forget _________ the letter.
A. to send      B. send      C. sending      D. being sent
2. The chair looks very old, but in fact it is very comfortable to _________.
A. sit          B. sit on     C. be sat        D. be sat on
3. Is ______ necessary to return the book tomorrow?
A. this         B. that       C. it           D. which
4. I'm afraid they would not allow him ________ here.
A. to smoke     B. smoking   C. smokes      D. smoke
5. Mother told me ________ the water before I drank it.
A. boiling       B. boiled    C. boil          D. to boil
6. On my way home, I stopped _______ some food.
A. buy         B. to buy     C. buying       D. bought
7. John was made _______ the car for a week as a punishment.
A. to wash      B. washing   C. wash        D. to be washing
8. The sitting-room needs _______, but it'll have to wait until Saturday.
A. be cleaning    B. to be cleaned    C. clean      D. being cleaned
9. The first thing I want to do is __________.
A. visit to him   B. to visit him    C. visiting him    D. visited him
10. Li Yang advised me _________ too much, otherwise I would have been drunk.
A. not to drink    B. to drink    C. not drinking    D. drinking
根据上句意思完成下句，使两句意思相近或相同，每空一词。
    1. He was so angry that he couldn’t say anything.
       He was too angry _______ ______ anything.
    2. I don’t know when we will have the meeting.
       I don’t know when _______ _______ the meeting.
    3. He said he would write a letter.
       He said he would have a letter ______ _______.
    4. That you read English in the morning is very important.
       It is very important _____ you _____ _______ English in the morning.
    5. He was so strong that he could lift the stone. （石头）
       He was strong _____ _____ ______ the stone.
    6. His father went to Beijing for his holiday.
       His father went to Beijing ________ ______ his holiday.
    7. They got up early so that they could get there in time.
       They got up early _____ ______ _______ ______ there in time.
    8. His brother decided that he would buy the book.
       His brother decided _____ _______ the book.
    9. He hopes that he can visit the Great Wall.
       He hopes _____ _______ the Great Wall.
    10.I saw him go into the room.
       He was seen _____ ______ into the room.
    11.We made him work five hours a day.
       He was made _____ ______ five hours a day.
    12.Do you want to say anything for yourself?
       Do you have anything _____ _____ for yourself?
    13.We don’t know what we shall do next.
       We don’t know what ____ _______ next.
    14.I’m very sorry on hearing the bad news.
       I’m very sorry _____ _______ the bad news.
    15.He stopped and had a look at me.
       He stopped _____ ______ a look at me.
    16.I helped him with his English.
       I helped him _____ ______ English.
    17.My father promised （许诺）that he would buy me a bike.
       My father promised ____ ______ me a bike.
    18.The box is so heavy that I can’t carry it.
       The box is too