非谓语动词——不定式

1、非谓语动词不定式知识点回顾：在句子中充当除谓语以外的句子成分的动词形式叫做非谓语动词。非谓语动词分为三种形式：不定式，动名词和分词（分词包括现在分词和过去分词）。不定式与动名词，分词一样是动词的一种非谓语形式。它与动词原形同性，但它前面一般要带有一个不定式的符号“to”，为了把它与介词to分开，也叫小品词，无词性，有时不定式也不带to。在句中，除了不能作谓语外，可以担当其它任何成分：主语、宾语、表语、状语、定语和宾语补足语。在句中起名词、形容词和副词的作用。A。非谓语动词不定式时态语态一览表非谓语动词形式时态/语态主动形式被动形式不定式一般式to doto be done完成式to have

2、doneto have been done进行式to be doing×完成进行式to have been doing×否定形式：not + 不定式B。不定式在句中所能充当的成分：主语宾语表语定语状语补语不定式1.不定式作主语a.To see is to believe.b.To obey the laws is important.c.To finish so much homework in a day is impossible.当作不定式的主语较长时，常用it作形式主语而将真正的主语（不定式）放在谓语之后。It is important to obey the la

3、ws.常见的带形式主语it的句型有：句型一：It is easy (difficult, hard, important, possible, impossible, comfortable, necessary, better, right,wrong, foolish, wise, kind, cruel, nice, the first, the next, the last, the best, too much, too little, not enough) to do.例句：Its so nice to hear your voice.听到你的声音真高兴。Its necessar

4、y 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。句型二：It is a pleasure (pity, pleasant, thing, crime, an honour.) to do sth.句型三：It takes (sb.) some time to do sth.1.1在句型一中，常用for sb.或of sb.来作不定式的逻辑上的主语。由以下两个方面决定for和of的使用。两者所使用的形容词不同A。for sb.的句型通常使用表示客观情况的形容词。例如：easy, difficult, hard,

5、important, possible, impossible, necessary, unnecessary, interesting等例句：It is important for us to express our opinion.It is easy for you to work out all the questions.B.of sb.的句型一般使用表示主观感情或态度的形容词。例如：good, kind, nice, wise, stupid, rude, clever, foolish, careful, polite, impolite, right, wrong, silly

6、, selfish等。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。 of sb.句型一般都可以换成一个不定式作状语的句子，而for sb. 句型不行。It is impolite of him to say so. = He is impolite to say so.It is important for him to say so. He is important to say so.所以，for与

7、of的辨别可用以下方法：用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for。如：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）1.2注意：（1）不定式作主语时，动词用单数形式。（2）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To see is to believe. 百闻不如一见。It is to believe to see. （错）2.不定式作表语不定式可放在be动词后面，形成表语。例如：My work is to clean the room eve

8、ry day.His dream is to be a doctor.Not to grasp firmly is not to grasp at all.What I want to do seems to tell you something.2.1常见的动词不定式作表语，一般紧跟在系动词如：be, remain, appear, get等后面，用来说明主语的内容。2.2常见的主语当我们用ones dream, business, wish, idea, plan, job, work, task, duty及what one wants to do等作主语时，常用不定式作主语。（见上例）

9、比较：主语（事物）+ be +不定式（作表语）表示主语的具体内容主语（人） + be +不定式（作表语）表示时态（将来时），为“即将”之意。He is to clean the room. 他即将去打扫房间。His plan is to clean the room. 他的计划是打扫房间。3.不定式作宾语3.1动词 + 不定式afford, aim, appear, agree, arrange, ask, be, decide, bother, care, choose, come, dare, demand, desire, determine, expect, elect, endeav

10、or, hope, fail, happen, help, hesitate, learn, long, mean, manage, offer, ought, plan, prepare, pretend, promise, refuse, seem, tend, wait, wish, undertake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。3.2动词 + 不定式； 动词 + 宾语 +

11、不定式ask, beg, choose, expect, hate, help, intend, like, love, need, prefer, prepare, promise, want, wishI like to keep everything tidy.我们喜欢每件东西都保持整洁。I like you to keep everything tidy.我喜欢你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。3.3动词 + 疑问词 + to动词不定式作动词tell, show

12、, undertand, explain, teach, learn, advise, discuss等词的宾语时，前面常带疑问词。即：疑问词（how, when, where, what, who） + to do例如：He showed us how to do the work.Please tell us what to do next.3.4介词宾语动词不定式在介词but, except, besides后面时，如果介词之前有行为动词do的某种形式，那么这些介词后的不定式不带to，否则就要带to。另外在cant choose but和cant help but等后面的不定式也省略to

13、。例如：We could do nothing but wait.We had nothing to do but wait.We have no choice but to wait.3.5不定式作宾语补足语动词不定式作动词feel, hear, see, watch, notice, observe等感官动词以及have, let, make等使役动词后面的宾语补足语时，不定式符号to要省掉，但如果这些句子变成被动结构时，就必须带to。如：I often hear him sing this song.He is often heard to sing this song.动词 + 宾语

14、+ 不定式（to do）advise, allow, appoint, believe, cause, challenge, command, compel, consider, declare, drive, enable, encourage, find, forbid, force, guess, hire, impel, induce, inform, instruct, invite, judge, know, like, order, permit, persuade, remind, report, request, require, select, send, state, s

15、uppose, tell, think, train, trust, understand, urge, warn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。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 in lying on the ground.I found it important to l

16、earn.I found that to learn English is important. 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, know, prove, see（理解），show, suppose, understand等。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。 to be

17、 + 形容词seem, appear, be said, be suppose, be believe, be thought, be known, be reported, hope, wish, desire, want, plan, expect, meanThe book is believed to be uninteresting.人们认为这本书没什么意思。注意：有些动词需要as短语作补语，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 too

18、k him as her father.玛丽把他当作自己的父亲。3.6不定式作定语不定式有时修饰前边的名词或代词，在句子担当定语，通常要放在被修饰的词后。例如：I have a lot of work to do. （名词是to do的逻辑上宾语）He is looking for a room to live in.作定语的不定式如果是不及物动词，或者不定式所修饰的名词或代词是不定式动作的地点、工具等，不定式后面须有相应的介词。例如：The Browns have a comfortable house to live in.There is nothing to worry about.P

19、lease give me a knife to cut with.Here is some paper for you to write on.但是，不定式所修饰的名词如果是time，please或way时，不定式后面的介词习惯上省去。例如：He had no money and no place to live (in).We found a way to solve this problem (in).当作定语的不定式所修饰的名词或代词是不定动作的承受者时，不定式既可以用主动语态，也可用被动语态，但其含义有所不同。试比较：Have you anything to send?你有什么东西要

20、寄吗？（不定式to send的动作执行者是“你”）Have you anything to be sent?你有什么要（我或别人）寄的东西吗？（不定式to be sent的动作执行者是“我”或“别人”）当不定式修饰want, have 等动词的宾语，而句子的主语是不定式的逻辑主语时，用主动语态表示被动含义。We have no homework to do.Mary has three babies to look after.当不定式修饰buy, get, give等动词的直接宾语，而间接宾语是不定式的逻辑主语时，用主动语态表示被动含义。Please buy me some newspape

21、r to read.请给我买几张可读的报纸。Ill give you some novels to read on the journey.我给你几本小说，你在旅途中阅读。4.不定式作状语4.1目的状语He sat down to have a rest.（表目的）放在句首，加强语气To serve the people well, I study hard.为了更好地为人民服务，我好好学习。4.1.2 in order to do, so as to do表目的She took a bus in order not to be late.She took a bus so as no to

22、be late.注意：强调动词不定式所表示的目的时，动词不定式可用in order to（为了）或so as to（以便）+ 动词原形。so as to 不用于句首。He got up early in order to catch the first bus.The bus stopped so as to pick up passengers.4.2结果状语：表结果，表事先没有预料到的，不定式要放在句子后面。不定时经常和only, never连用，强调结果和失望的情绪。I hurried to get there only to find him out.我匆匆忙忙地赶到那儿，（没想到）他

23、出去了。After that day they were separated, never to see each other again.那天他们被分开之后，再没见过面。4.3原因状语：表原因。不定式可以在表示感情的形容词后面来修饰该形容词，表示原因。常用于这种结构的形容词和过去分词有：happy, glad, delighted, pleased, sorry, eager, anxious, lucky, fortunate, proud, foolish等。Im glad to see you.修饰表示情感以外的形容词用于这类结构中，常用的形容词有：easy, difficult, h

24、ard, comfortable, pleasant。而此种句子的主语可以是人，也可以是物。例：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。4.4在带有enough或too的句子里，也常用不定式作状语，表示程度。例如：He was too excited not to say a few words.他太激动了，不会

25、不讲几句话的。He is old enough to go to school.他到上学年龄了。She is too tired to do the job.她太累而不能做那件工作了。5.不定式在句中作为独立成分有时不定式在句中作为独立结构出现，用来说明说话人的态度。一般来讲，可用固定词组和固定搭配来运用。To tell you the truth, I have got no money about me.To be honest, I know nothing about it.6. 省to的动词不定式6.1情态动词（除ought外，ought to）6.2使役动词let, have, m

26、ake6.3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.6.4 would rather, had better6.5 Why./ why not例：I usually go there by

27、train.Why not _by boat for a change?A. to try going B. trying to go C.to try and go D.try going答案：D。why not 后面接不带to的不定式，因此选D。6.6 help可带to，也可不带to，help sb (to) do sth.6.7 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。He wants to do nothing but go out.6.8由and, or和than连接的两个不定式，第二个to可以省去。He wants to move to F

28、rance and marry the girl.6.9通常在discover, suppose, think, understand等词后，可以省去to be。He is supposed (to be ) nice.他应该是个好人。7.不定式的特殊句型too.to.7.1 too.to 太以至于.He is too excited to speak.7.2 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”。Its never too late to mend.（谚语）改过不嫌晚。7.3当too前面有only, all, but时，意思是：非常.

29、等于very。Im 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.我非常想回家。8.不定式的时态和语态8.1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 Ill see you again.8.2完成时：表示的动作发生在谓语动词表示的动作之前。Im sorry to have given you so much

30、 trouble.He seems to have caught a cold.8.3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.8.4完成进行时：表示从过去到现在仍然进行的动作。She is known to have been working on the problem for many years.8.5在intended, expected, hoped, promised, wanted, wished, thought等后用不定式完成时，表示过去没有实现的愿望、期待或计划等，也表示发生在位于动作之前的动作状态。I intended to have come to see you.I hoped to have finished the work earlier.8.6在seem, appear, think, consider, believe等表示看法与想法的动词后用不定式完成时，表示该动作先于另一个动作。此结构也常以it作形式主语的结构代替。He seems to have bought the new book.= It seems that he has bought the new bo