动词不定式是非谓语动词的一种重要形式。不定式的形式为 to do sth. 其中, to 是不定式的标志, do 表示在不定式中动词用原形。
由于不定式中有动词, 所以不定式也可以有自己的状语、宾语等成份, 例如：to study hard, to help me with my maths 等等, 这叫做不定式短语, 即不定式词组。
不定式中的动词do 通常为原形动词, 即没有人称数的变化、没有时态的变化。但这不是绝对的。不定式中动词do 也会时态的变化, 一般有三种形式即不定式的进行态、完成态、被动态, 请大家结合下面的讲解加以注意。
下面, 就动词不定式运用中要注意的问题谈几点注意事项。
1. to 是不定式标志, 还是介词？
有些谓语动词, 结尾也带着一个to, 但是这个to 不表示后面要接不定式, 而是介词。请记住：如果to 是介词的话, 后面就要接名词性词组, 如果后面接动词的话, 就不能用原形动词, 而要接动名词, 即要用v-ing 形式。常见的结尾带介词to 的动词有：agree to, object to, close to, come to, lead to, refer to, equal to, familiar to, point to, thank to, devote to, next to, belong to, be used to, look forward to 等。
例1：object to
China and India formally objected to the peace plan. [objected to +名词]
中国和都正式反对那项和平计划。
I object to paying that much for gas. [objected to +动名词]
我反对为煤气要付那么多钱。
He object to being treated like this. [objected to +动名词]
他反对受到那样的对待。
例2：look forward to
We look forward to the return of spring. [look forward to +名词]
我们期待着春天的到来。
I am familiar with his work and look forward to hearing his views on Literary and artistic creation. [look forward to +动名词]
我熟悉他的作品, 并期待他能就文艺创作问题发表自己的见解。
He was looking forward to working with the new Prime Minister. [look forward to +动名词]
他正盼望与新首相共事。
2. 动词不定式要to 还是省略to?
动词不定式前面一般都有to, 即to do sth. 但有些情况下可以省略不定式前面的to. 要说明一点：省略不定式to 的情况比较复杂, 请参看本站有关文章。这里只把这个问题提出来, 引起大家注意而已。例如：
I can not but admire his courage。
我不得不佩的勇气。
He did nothing at the meeting but smoke.
他在会上什么也没干只是吸烟。
I have nothing to do except copy the artecle for hi m.
我只好给他抄写这篇文章。
I have no choice but to give in.
除了让步, 我别无选择。
3. 动词不定式的逻辑主语用for 还是of ?
动词不定式逻辑主语通常用for sb. 来表示, 但也有用 of 的。例如：
Its necessary for you to study hard .
努力学习对你很有必要。
It’s foolish of him to do it .
他这样做太愚蠢了。
为了不使大家混淆, 这里把常与of 连用的形容词列出来, 它们是：good, kind, nice, wise, clever, foolish, right, wrong, careful, careless, polite, possible 等。
4. 接不定式还是接动名词？
谓语动词后可以接不定式, 也可以接动名词, 所以这一点往往让人混淆。很多文章对这个问题作了归类, 请大家自己去看一下。下列这些动词一般只接不定式：
afford 负担得起; arrange 安排; ask 要求; care 想要; choose 决定; decide 决定; demand 要求; determine 决心; expect 期待, 预计; help 帮助; hesitate 犹豫; hope 希望; long 渴望; manage 渴望设法; offer 主动提出; plan 计划; prepare 准备; pretend 假装; promise 答应; refuse 拒绝; want 想要; wish 希望, 等。例如：
Can you afford to lend me some money?
你能借出一些钱给我吗?
We’ve decided to hold a meeting.
我们决定召开一个会议。
He demanded to know the truth.
他要求知道事实真相。
He determined to learn French.
他决定学法语。
5. 回答中不定式的省略形式是什么?
在疑问句的回答中, 常常可以用不定式的省略形式来回答。在意义明确的前提下, 下列动词常常可以用省略回答形式：want to, wish to, hope to, like to, hate to, plan to, try to, love to , have to, ought to, need to, used to, be able to 等。
例如：
Would you like to come to our party on May 12?
Yes, I like to.
6. 不定式可以用哪些句子成份？
除了不能做谓语, 不定式几乎用作句子的任何成份, 例如：定语、状语、补语等。这里只举几个例子说明一下, 详细用法请参看本站有关文章。
(1) 做定语
He has a lot of meeting to attend .
She is always the last (person) to speak at the meeting .
(2) 做状语
He is lucky to get here on time .
He came to help me with my maths .
I hurried to get there only to find him out.
(2) 做补足语
I saw him play in the street just now .
He was seen to play in the street just now.
[附：典型例题讲解]
1. I’m going to the supermarket this afternoon. Do you have anything ________ ?
A. to be buying B. to buy C. for buying D. bought
答案：B 解析：不定式做定语。
2. They had nothing else to do but________ a doctor.
A. call for B. to send C. to call on D. send for
答案：A 解析：不定式做介词宾语。
3. Robert is said________ abroad, but I don’t know what country he studied in.
A. to have studied B. to study C. to be studying D. to have been studying
答案：A 解析：不定式的完成态。
4.The purpose of new technologies is to make life easier,________ it more difficult.
A. not make B. not to make C. not making D. do not make
答案：B 解析：不定式做表语。
5. There are five pairs ________, but I’m at a loss which to buy.
A. to be chosen from B. to choose from C. to choose D. for choosing
答案：B 解析：不定式做定语。
6. He hurried to the station, _________ the train had left.
A. having found B. unfortunately found C. finding D. only to find
答案：D 解析：不定式做状语。
7. Tom did whatever he could________ those who were in trouble.
A. to help B. help C. helping D. do help
答案：A 解析：不定式做状语。
8. The way they talked________ the problem seemed impossible.
A. about settling B. to settle C. of settling D. about to settle
答案：D 解析：不定式做定语。
9. Every minute is made full________ of________ our lessons well.
A. to use; study B. use; studying C. use; to study D. used; studying
答案：C 解析：不定式做状语。
10. The old man was once________ sing the song.
A. listened to B. listening to C. listened to to D. listen to
答案：C 解析：不定式做补语。
[巩固练习题]
I. Multiple Choice
1. Most of the people _____ to the party were famous scientists.
A. invited B. to invite C. being invited D. inviting
2. ______ many times, but he still couldn’t understand it .
A. Having being told B. Though had been told
C. He was told D. Having told
3. She reached the top of the hill and stopped _____ on a big rock by the side of the path .
A. to have rested B. testing C. to rest D. rest
4. The next morning she found the man ______ in bed , dead .
A. lying B. lie C. lay D. laying
5. The purpose of new technologies is to make life easier , _______ it more difficult .
A. to make B. not to make C. not making D. to not make
6. The Olympic Games , _____ in 776 B.C., did not include women plays until 1912.
A. first playing B. to be first played
C. first played D. to be first playing
7. —You were brave enough to raise objections at the meeting .
— Well, now I regret ____________that.
A. to do B. to be doing C. to have done D. having done
8. The visiting Minister expressed his satisfaction with talks, _______ that he had enjoyed his stay here.
A. having added B. to add C. adding D. added
9. _______ a reply, he decided to write again.
A. Not receiving B. Receiving not
C. Not having received D. Having not received
10. The speaker raised his voice, but he still couldn’t make himself ________.
A. hear B. to hear C. hearing D. heard
II. Filling in the blanks with proper forms
1. Little Tom should love ________(take) to the theatre this evening.
2. Paul doesn’t have to be made _______(learn) . He always works hard.
3. The computer centre , ______(open) last year , is very popular among the students in this school.
4. Go on _____(do) the other exercise after you have finished this one.
5. How about two of us ______(take) a walk down the garden.
[Keys]
I. 1-5 ACCAB 6-10 CDCCD
II. 1. to be taken 2. to learn 3. opened 4. to do 5. taking
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