英语语法大全-7. 动词不定式


7.1 不定式作宾语

1) 动词+ 不定式
afford  aim   appear  agree  arrange  ask   be    decide bother  care  choose   come    dare   demand desire  determine     expect   elect  endeavor     hope       fail  happen  help  hesitate learn  long   mean   manage  offer  ought   plan  prepare pretend   promise refuse seem   tend   wait    wish     undertake
 The driver failed to see the other car in time.
 I happen to know the answer to your question.

2)动词+不定式 ; 动词+宾语+不定式
ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wish…
 I like to keep everything tidy. 我喜欢每件东西都保持整洁。
 I like you to keep everything tidy. 我喜欢你年使每件东西都保持整洁。
I want to speak to Tom.  我想和汤姆谈话。
I want you to speak to Tom.  我想让你和汤姆谈话。

3) 动词+疑问词+ to
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。

   The question is how to put it into practice.

7.2 不定式作补语

1) 动词+宾语+不定式(to do)
advise   allow   appoint   believe   cause   challenge command  compel   consider  declare   drive   enable  encourage  find    forbid   force   guess   hire    imagine  impel   induce   inform  instruct  invite   judge    know    like   order    permit  persuade  remind   report  request   require  select send    state   suppose   tell    think  train   trust   understand urge    warn 

  a. Father will not allow us to play on the street.       
  b. We believe him to be guilty.

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.

  The next morning she found the man ___ in bed,dead. 
  A. lying  B. lie  C. lay  D. laying  

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.

   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.

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。

注意 : 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。

7.3 不定式主语

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.
 It's necessary for you to lock the car when you do not use it.

2) It's very kind of you 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)
   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. 百闻不如一见。
    (错)It is to believe to see.

7.4 It's for sb.和 It's of sb.

1)for sb. 常用于表示事物的特征特点,表示客观形式的形容词,如easy, hard, difficult,  interesting, impossible等:
   It's very hard for him to study two languages. 对他来说学两门外语是很难的。
2)of sb的句型一般用表示人物的性格,品德,表示主观感情或态度的形容词,如good, kind, nice, clever, foolish, right。
   It's very nice of you to help me. 你来帮助我,你真是太好了。

for 与of 的辨别方法:
   You are nice. (通顺,所以应用of)。
   He is hard. (人是困难的,不通,因此应用for。)

7.5 不定式作表语

   My work is to clean the room every day.
   His dream is to be a doctor.

7.6 不定式作定语

   I have a lot of work to do. 
   So he made some candles to give light.

7.7 不定式作状语

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。

  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.

 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。

7.8 用作介词的to

  to 有两种用法: 一为不定式+动词原形; 一为介词+名词/动名词, to 在下面的用法中是第二种,即to+ 名词/动名词:

admit to承认,       confess to承认,
be accustomed to 习惯于,  be used to 习惯于, stick to 坚持,       turn to开始,着手于, devote oneself to 献身于, be devoted to 致力于, look forward to 盼望,   pay attention to 注意

7.9 省to 的动词不定式

1) 情态动词 ( 除ought 外,ought to):
2) 使役动词 let, have, make:
3) 感官动词 see, watch, look at, notice , observe, hear, listen to, smell, feel, find 等后作宾补,省略to。

注意:在被动语态中则to 不能省掉。
  I saw him dance.
 =He was seen to dance.
  The boss made them work the whole night.
 =They were made to work the whole night.
4) would rather,had better:
5) Why… / why not…:
6) help 可带to,也可不带to, help sb (to) do sth:
7) but和except:but前是动词do时,后面出现的动词用不带to的动词不定式。
8) 由and, or和than连接的两个不定式,第二个to 可以省去

7.10 动词不定式的否定式

  Tell him not to shut the window… 
  She pretended not to see me when I passed by. 我走过的时候,她假装没看见。

1)Tell him ___ the window. 
  A. to shut not  B. not to shut  C. to not shut
  D. not shut 
  答案:B。 tell sb to do sth 的否定形式为tell sb not to do sth.

2) She pretended ___ me when I passed by. 
  A. not to see  B. not seeing  C. to not see
  D. having not seen 
  答案:A。 pretend 后应接不定式。其否定形式为pretend not to do sth.。

3)Mrs. Smith warned her daughter ___ after drinking. 
  A. never to drive  B. to never driver 
  C. never driving  D. never drive 
  答案:A。warn sb to do sth. 的否定形式为warn sb not to do sth. 此处用的是否定词never.

4) The boy wanted to ride his bicycle in the street,but his mother told him ____. 
  A. not to  B. not to do  C. not do it 
  D. do not to
 答案:A。not to 为not to do it 的省略形式。可以只用to这个词,而不必重复整个不定式词组。及物动词do后应有名词、代词等,否则不对,因此B,D不对。

5) The patient was warned ___ oily food after the operation. 
  A. to eat no  B. eating not  C. not to eat 
  D. not eating
  答案:C。warn一词要求后用不定式,此处为不定式的被动,否定形式为be warned not to do。

7.11 不定式的特殊句型too…to…

1)too…to  太…以至于…
  He is too excited to speak.
  ---- Can I help you ? 需要我帮忙吗?
  ---- Well, I'm afraid the box is too heavy for you to carry it, but thank you all the same. 不用了。这箱子太重,恐怕你搬不动。谢谢您。

2) 如在too前有否定词,则整个句子用否定词表达肯定, too 后那个词表达一种委婉含义,意 为"不太"。
  It's never too late to mend. (谚语)

3) 当too 前面有only, all, but时,意思是:非常… 等于very。
  I'm only too pleased to be able to help you. 我非常高兴能帮助你。
  He was but too eager to get home. 他非常想回家。

7.12 不定式的特殊句型so as to

1) 表示目的;它的否定式是so as not to do。
   Tom kept quiet about the accident so as not to lose his job. 
   Go in quietly so as not to wake the baby.

2) so kind as to ---劳驾
   Would you be so kind as to tell me the time?

7.13 不定式的特殊句型Why not

  "Why not +动词原形"表达向某人提出建议,翻译为:"为什么不……?" "干吗不……?"
   Why not take a holiday?

7.14 不定式的时态和语态

时态\语态    主动     被动
一般式      to do      to be done
进行式      to be doing  
完成式      to have done   to have been done
完成进行式    to have been doing  

1) 现在时:一般现在时表示的动词,有时与谓语动词表示的动作同时发生,有时发生在谓语动词的动作之后。
  He seems to know this.
  I hope to see you again. = I hope that I'll see you again. 我希望再见到你。

2) 完成时:表示的动作发生在谓语动词表示的动作之前。
 I'm sorry to have given you so much trouble.
 He seems to have caught a cold.

3) 进行时: 表示动作正在进行,与谓语动词表示的动作同时发生。
 He seems to be eating something.

4) 完成进行时:
 She is known to have been wreaking on the problem for many years.

7.15 动名词与不定式

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) 动名词与不定式语义不同的有11 组:
  1 stop to do     stop doing   
  2 forget to do     forget doing
  3 remember to do   remember doing     
  4 regret to do     regret doing
  5 cease to do     cease doing       
  6 try to do      try doing
  7 go on to do     go on doing       
  8 afraid to do     afraid doing
  9 interested to do  interested doing 
 10 mean to do      mean doing
 11 begin/ start to do  begin/ start doing