1、动词不定式用法讲解1、构成及特征动词不定式(infinitive)是动词的一种非限定形式，即非谓语动词形式，它有两种形式：一种是“to + 动词原形”构成（to- infinitive）；另一种是不带 to 的不定式,即动词原形(bare- infinitive)。所有行为动词都有不定式形式，其否定式是在不定式前加 not。动词不定式（或不定式短语）没有人称和数的变化，在句子中不能作谓语。动词不定式仍保留有动词的特点：（1）可以有时式和语态的变化，也可以有自己的宾语或状语，它们一起构成了不定式短语。He tried to work out the problem in five minutes
2、.他试图在五分钟之内算出这道题。（带宾语和状语）The factory to be built here next year is a car factory.明年在这里建的工厂是一家汽车制造厂。（有语态的变化）（2）动词不定式还具有名词、形容词和副词的特征，在句中可以作主语、宾语、表语、补语、定语、状语等成分。He wants to study English.他想学英语。（to study English 在句中作 want 的宾语，而to study 又有自己的宾语 English, to study 和 English 一起构成了不定式短语。）Never to offend anyon
3、e is his principle.不得罪人是他的原则。（不定式作主语）注意：不定式在许多场合具有情态意义。作主语时，相当于一个带有情态动词的主语从句；作宾语时，相当于一个带有情态动词的宾语从句；作定语时，相当于一个带有情态动词的定语从句；作目的状语时，相当于 so that 或 in order that 引导的目的状语从句。It is right for her to say so.(= It is right that she should say so.)她这样说是对的。He has a lot of work to do.(= that he should do)他有很多工作要做。
4、I dont know where to get the ticket.(= where I could get the ticket.)我不知道哪里能买到票。She opened the door for the children to come in.(= so that the children might come in)她打开门目的是让孩子进来。2、动词不定式的时态和语态动词不定式有一般式、进行式、完成式、完成进行式四种时态变化形式，一般式和完成式有被动语态变化形式。 主动语态 被动语态一般式 to write to be written进行式 to be writing 完成式 t
5、o have written to have been written完成进行式 to have been writing （1）不定式的时态意义不定式的时态是以句中谓语动词的时间为依据的。不定式的一般式不定式的一般式表示的动作或状态通常发生在谓语动词之后或同时发生。They made plans to live in Paris.他们计划住在巴黎。（ to live 发生在 made plans 之后）I heard them talk in whispers all the time at the meeting.我听见他们会议期间一直小声说话。（不定式 talk 与谓语动词 heard
6、同时发生）不定式的进行式不定式的进行式表示其动作正在进行，与谓语动词发生的动作同时进行。He pretended to be listening to me carefully.他假装认真地听我讲。When he came in ,I happened to be reading the novel.他进来时，我碰巧正在读小说。注意：不定式的进行式常同 may, might, can, could, must, need, ought to, should, will, would 等情态动词连用，表示“可能、应当或想必”正在进行的动作。You oughtnt to be talking so
7、 much. 你不应该说这么多。He might be reading a novel at that time. 那时他可能正在读小说。It is good to sit here with you.(坐下来时讲这句话)It is good to be sitting here with you.(一坐在座位上时讲这句话)He is said to write a preface to the book.(表示将来)He is said to be writing a preface to the book.（表示进行）不定式的完成式不定式的完成时表达下列意义：a. 不定式的完成式所表示的动
8、作或状态发生在谓语动词所表示的动作之前。I am sorry to have kept you waiting.对不起，让你久等了。（to have kept 发生在 I am sorry 所表示的时间之前）She is said to have just completed a novel.据说她刚完成一部小说。（ to have just completed a novel 发生在 She is said 所表示的时间之前）b. 用在 intended, expected, meant, hoped, promised, planned, wished, thought, desired,
9、 was, were 等词后，不定式的完成式表示未曾实现的愿望、期待、想法、打算或计划等。to have + 过去分词表示动作， to have been 表示状态。I meant to have done the work before Sunday.我本想星期天前完成这项工作。（没完成）I was to have been a doctor.我本打算当个医生。（没当成）I intended to have come to see you.我本打算来看你的。(但没来)C .用在 seem, appear, thing, consider, believe 等后，表示一个动作先于另一个动作发生
10、。I seem to have seen her somewhere before.以前我好像在那见过她。（ see 在 seem之前发生）He was believed to have been a reporter.都认为他从前干过记者。比较：She seems to have been ill.= It seems that she has been ill.她似乎病了。She seemed to have been ill.= It seemed that she had been ill.她似乎过去生过病。d. 在 should(would) like 或 should(would)
11、have like 后用不定式完成式表示没有实现的愿望。I should like to have gone with her.我多么愿意和她一起去。（但没去）I would like to have seen her face when she read the letter.我真想见到她读信时的表情。（但没看到）不定式的完成进行式表示动作在谓语动词之前发生，而且一直进行着。He was happy to have been staying with his uncle.他很高兴一直跟他叔叔住在一起。He looked too young to have been publishing bo
12、oks for six years.他看上去很年轻，不像已经出版了 6 年书的人。 come + 不定式表示一个动作发生的过程He will come to understand it in the end.他最终会懂得的。Later he came to be a famous painter.后来他成了著名的画家。（2）动词不定式的被动语态如果不定式的逻辑主语是不定式动作的执行者不定式用主动式；如果不定式的逻辑主语是不定式动作的承受者时，不定式用被动语态。The doctor recommended him to air the room.医生建议他让房间透透气。（主动式）The doct
13、or recommended the room to be aired. 医生建议让房间透透气。（被动式）The sports meeting on the weekend has to be put off.周末的运动会被迫推迟。（被动式）What is to be done next?下一步干什么？（被动式）（3）意义上被动形式上主动的不定式 在“there be+主语”中，不定式用作定语修饰名词或代词，并同所修饰的名词或代词是逻辑上的动宾关系。There is no time to lose.一点时间也不能浪费了。There are a lot of clothes to wash.有许
14、多衣服要洗。There is nothing to do at the moment. 暂时无事可做。在“名词（代词） be easy(difficult, fit 等形容词) 不定式”结构中，有时尽管主语是动作的承受者，不定式在意义上是被动，形式上却是主动，这时可以看成省略了动词逻辑主语 for us, for me , for you 等。The book is difficult to read. 这本书很难读懂。He is not easy to get on well with. 他不易相处。如果不定式逻辑主语是不定式动作的执行者，不定式和它修饰的名词虽然在逻辑上有动宾关系，也必须用
15、主动形式，因为逻辑主语同不定式的关系更为直接。Weve got plenty to eat.我们有足够的东西吃。（句子主语 We 在逻辑上是不定式 to eat 动作的执行者，不定式 to eat 和它修饰的名词 plenty 在逻辑上是动宾关系，用主动形式表示被动意义。）Most people have some similar experience to remember. 大多数人都有一些相似的体会值得记忆。（句子主语 Most people 在逻辑上是不定式 to remember 动作的执行者，不定式 to remember 和它修饰的名词 experience 在逻辑上是动宾关系，
16、用主动形式表示被动意义。）注意：不定式和句中主语或其它成分如果不是逻辑上的主谓关系，不定式仍宜用被动形式。He described the black slaves to be sold at auction.他描写了那些被拍卖出售的黑人奴隶。We thought the meeting to be held very important.我们认为即将举行的会议很重要。在 too to 和 enough to 结构中，不定式可用主动语态表示被动意义。The box is too heavy to carry.这个箱子太重了搬不动。The book cheap enough to buy.这本书
17、很便宜可以买。blame 的不定式作表语时，用主动语态和被动语态表示被动的意义，但含义不同。You were to blame. （= you are at fault.）这该怪你。You were to be blamed.(= You are going to be blamed.)你要受到指责。something, little, what, much, a great deal 等作句子主语，表语为 to do 时，不定式可用主动语态表示被动意义。A great deal of work remains to do.还有很多工作要做。What is to do tomorrow? 明天
18、干什么？to let 表示“出租”作表语时，可用 to be let 形式，但含义上有些差别。This house is to let. 此房出租。（从房屋主人的立场讲话，由于房子主人亲自向租房人说或登出广告）This house is to be let. 此房出租。( 从房屋本身来说，代理人向租房人讲话)a. 不定式和它所修饰的词必须是逻辑上的动宾关系，如果是逻辑上的主谓关系，意义不是被动而是主动。They have the ability to change things for the better.他们具有使事态好转的能力。Its a picture to guide you.这是衣
19、服可以指引你的图。b. 在同一场合，某些不定式可用主动形式或被动形式，但含义常有细微差别。主动形式经常带有一定的情态意义，如可能、必要、应该等，而被动形式则不带情态意义。例如：There is nothing to see. 没有什么值得看的。（指没有东西可看）There is nothing to be seen. 什么也看不见，（指没有东西被看见）c. 如果不定式与其逻辑主语或被修饰的名词之间存在逻辑上的动宾关系，而不定式中的动词是不及物动词或虽是及物动词，而其本身已经带有宾语的，则不定式后应加一个合适的介词。I have no paper to write on.我没纸写字。I need
20、 a chair to sit on.他需要一把椅子坐下。d. 下列句型必须用被动式Theres still much left to be described.还剩很多要描述。There is no sound to be heard.没听见声音。3、动词不定式的句法功能动词不定式具有名词、形容词和副词的特征，因此在句中可以作主语、表语、宾语补足语、定语和状语。（1）不定式作主语 To make a plan first is a good idea.先制订计划是个好办法。To die for our motherland is a great honour.为祖国而死，死得光荣。不定式及不
21、定式短语作主语时，为了平衡句子结构，可用 it 作形式主语，而把真正的不定式后置。It is a good idea to make a plan first .首先制订一个计划是一个好主意。Its a great pleasure to see you again.再次见到你太好了。Its bad manners to stare at a foreign guest.盯着外国人看是不礼貌的。在下列情况下只宜采用 it 作形式主语a. 在疑问句或感叹句中作主语的不定式。Isnt it a good idea to set up a lab of our own?建一座我们自己的实验室不是个好
22、主意吗？How important it is to master a foreign language!掌握一门外语是多么重要啊 !b. 当句中谓语动词不是 be, seem, appear 等连系动词时。It took us 20 minutes to get to the station.赶到车站花了我们 20 分钟。It made the boy greatly pleased to get the gift.得到礼物使男孩大为高兴。c. 在“it +be + adj.+ of + sb.+不定式”结构中。Its very nice of you to help me with my
23、work.帮我的工作，你真是太好了。It was silly of us to do so.我们这样做真是太傻了。d. 有时候，作主语的不定式相当于一个条件从句。To love others is to be loved. If you love others you will be loved by others.爱人即爱己。To build an expressway across the country requires a lot of money.= If you build an expressway across the country, it will require a lo
24、t of money.建一条贯通全国的高速公路需要很多钱。e.如果作主语的不定式短语是及物动词宾语，则可以把宾语转换为主语，而不定式移到句尾。To revise the poem took her two weeks. = The poem took her two weeks to revise.修改这首诗花了她两周的时间。（the poem 是 revise 的逻辑宾语）To talk with Helen is interesting.= Helen is interesting to talk with.同海伦谈话很有趣。（2）不定式作表语主语、表语都是不定式，前者是条件，后者是目的或
25、结果。To learn a language is to use it.学语言是为了使用语言。To be kind to the enemy is to be cruel to the people.对敌人仁慈就是对人民残酷。主语是 duty, plan, wish, hope, idea, purpose 等名词。His wish was to become a scientist.他的愿望是当一名科学家。To the doctor ,the most important thing is to save peoples lives.对医生来说，最重要的事是拯救人们的生命。表示时态发展的结果
26、、预期的结果、不幸的命运或预言。You are to die at 98.你会 98 岁去世。Man is to live a better life in the next century.人类在下一世纪会生活的更好。表示“同意、安排、命令、决定、劝告、意愿 、禁止”等。They are to marry next week.（安排）他们下周结婚。Nobody is to know.（禁止）不应让任何人知道。You must be patient and persistent if you are to succeed.（愿望）要想成功，就必须有耐力，有毅力。主语是 what 引导的名词性从
27、句。What surprised me most is to see him beaten black and blue.使我吃惊的是看到他被打得遍体鳞伤。What is important at present is to save lives.目前救人要紧。（3）不定式作宾语有些及物动词常跟不定式作宾语，如 agree, afford, arrange, ask, begin , decide, forget, hope, like , start , want, wish 等。She wanted to borrow my bike.她想借我的自行车。They began to read
28、 and write.他们开始读写。不定式也可用来作形容词的宾语，如 able, afraid, anxious, careful, content, determined, eager, foolish, free, glad, inclined, likely, pleased, prepared, ready, slow, sure, sorry, willing 等。The boys and girls are anxious to learn how to swim.孩子们渴望学会游泳。Im glad to meet you.见到你我很高兴。a. 不定式作宾语时，句子的主语是不定式的
29、逻辑主语，与不定式动词的关系是主动关系，但有时不定式和主语却是动宾关系。English is not difficult to learn.英语不难学。The question is easy to answer.这个问题很好回答。b. feel, find, judge, make, think, believe, consider 等动词后如果是不定式作宾语，后面有宾语补足语时，将真正的宾语不定式放在补足语的后面，而将形式宾语 it 放在补语之前。He found it hard to learn maths.他发现数学很难学。I think it our duty to support
30、the elder.我认为赡养老人是我们的义务。（4）不定式作定语不定式作定语时，需放在它所修饰的名词或代词之后。它与所修饰的名词或代词有下列关系：动宾关系Have you got anything to say?你有什么要说的吗？She did not have much money to spend.她没有更多的钱花。注意：如果不定式的动词是不及物动词，和所修饰名词搭配的介词不能省略。He had no room to live in.他没房子住。There are 60 desks for us to sit by.有六十张桌子供我们坐。主谓关系He is always the firs
31、t to come and last to leave.他总是第一个来，最后一个走。The next train to arrive is from Washington.下一列到站的火车是从华盛顿开来的。同位语关系The farmers thought of ways to protect their crops.农民们想出保护庄稼的办法。He had the wish to be an artist. 他愿意当艺术家。a. 不定式可以修饰 there be 结构中作主语的名词There is nothing to worry about.没什么可担心的。There is enough mo
32、ney to spare.钱足够用。b. 有些动词和形容词后常跟不定式，这些词派生出来的名词 ability, agreement, anxiety, attempt, claim, decision, determination, eagerness, need, plan, promise, tendency, willingness, wish, impatience, inclination 等常跟不定式作定语, 这类词后的不定式常表同位关系She had a tendency to talk too much.她喜欢唠叨。His eagerness to get back home
33、was quite obvious.看的出，他急于回家。（5）不定式作状语不定式作状语时，常表示目的、结果、原因、条件等，通常放在它所修饰的动词之后。表目的不定式作目的状语时，其动作发生在谓语动词之后，一般放在句子后部。但如要表示强调，也可以位于句首，前面可加 in order,不定式作目的状语时其否定必须用 in order not +不定式，或 so as not 不定式。 in order to 引出的不定式可置于句首或句中， so as not不定式不能放在句首，只能放在句中。He stopped to have a rest.他停下来休息。（目的）To search for gold
34、, many people went to California.为了寻找金子，许多人去了加利福尼亚。（目的）I often read China Daily so as to improve my reading.我常读中国日报以提高我的阅读。（目的）We often listen to English broadcasts to/in order to/so as to get listening training.我们经常听英语广播，以增强听力训练。此句可改变：To/In order to （但不能用 so as to）get listening training, we often l
35、isten to English broadcasts.比较：在英语中，目的一般用不定式表示，而不用 for动名词或者分词表示。She has phoned to say that she will resign.她打电话说她要辞职。（不用 for saying）We eat to live.我们吃饭是为了生存。（不用 for eating）To pass the exam, he worked hard at his lesson.为了能通过考试，他刻苦读书。 (此处不能用 Passing the exam)表示结果A few days later he came back only to
36、find that the troop had left.他几天后回来，发现部队已经离开了。（不定式动作后发生）She tried to kill herself only to be saved.她企图自杀，后来被救了。（常代 only 一词表明是结果）Few people live to be a hundred years old.很少有人能活到一百岁。a. 形容词如 right, polite, crazy, generous, good, greedy, kind, selfish, silly, splendid, nice, unselfish, unkind 等对人进行表扬或批
37、评，后接不定式表示结果，不定式的逻辑主语也就是句子主语。He is very polite to show us the way.他很有礼貌给我们指路。He is silly to say so. 他这么说太傻了。b. 不定式和 only 连用，表示未预料到的结果。He woke up only to find himself famous.他一觉醒来，竟发现自己成名了。The thief broke into the house only to find it empty.小偷闯进屋子，却发现是空的。c.在 so as to, such as to, enough to 等结构中的不定式皆表
38、示结果。He is too young to join the army.他太年轻了，不能参军。He is so careless as to forget his pen.她太粗心了，以至于把钢笔忘了带。d.“too to”表示结果意为：太 而不能 ，但有时不含否定意义。He is too excited to sleep.他太激动了，不能入睡。（否定）We are only too pleased to work together with you.我们同你一起工作，真是太高兴了。（肯定）You are too ready to find out fault with others.你太好
39、挑剔别人了。（肯定）表示原因，其逻辑主语是句子的主语。She wept to see him in such a terrible state.她看到他这种可怕的样子就哭了。The whole nation was in deep sorrow to learn the death of Lincoln. 听到林肯去逝的消息，全国都沉浸在悲痛之中。表示条件动词不定式有时也可以表示条件，一般置于句首，否定不定式表示条件多置于句尾，这时谓语动词常含有 will, shall, should, would, can, must 等。To hear him talk, you would think
40、he owned the whole world.要是听他讲话，你会认为整个世界都是他的。One would be careless not to see the mistake.如果一个人看不到自己的缺点他就会疏忽大意。表示伴随这种情况不定式常以独立结构出现。They divided the work, John to wash the vegetables and Mary to cook the meal.他们做了分工，约翰洗菜；玛丽做饭。A number of students sat around the professor, some to ask questions, some
41、to discuss among themselves.一些学生围着教授坐，有的问问题，有的自己讨论。表明说话人的态度， 在句中作独立成分。To tell the truth, this all Greek to me.说实话，我对此一窍不通。To make a long story short, he became bankrupt.简单的说，他破产了。To be true, we can do it well.当然，我们能做好。除此之外还有：to be brief 简而言之、to be exact 精确的说、to be frank with you 老实对你说 、to be plain 老
42、实说 、to put it straight 直截了当、to bring the story short 长话短说、to return to my subject 言归正传、to change the subject 换一个话题、to use his own words 用自己的话说、to make matter worse 更糟的是、to give him his due 公正地说、strange to say 奇怪地说、to say nothing of 姑且不讲、 to conclude 总之、to crown all 更好（坏）的是、to be honest 直率地说、to start
43、 /begin with 首先、to do him justice 说句公道话、 to sum up 总之，总而言之等。这些短语大都位于句首，偶尔位于句中或句尾，需要用逗号和其他成分隔开。但表示“更不用说”的几个短语一般要放在句尾，如 to say nothing of, not to say, not to mention, not to speak of, let alone, much less, much more 等。（6）不定式作宾语补足语和主语补足语不定式作宾语补足语时，宾语与不定式构成复合宾语，宾语是不定式的逻辑主语。Lucy asked him to turn down th
44、e radio.露茜叫他把录音机关得小一些。Jim told Ling Feng to give his best wishes to everybody.吉姆告诉凌峰转告他对每个人的衷心的祝愿。a. 动词 believe, consider, declare, find, prove, suppose, feel, think 等后面常跟 to be 不定式作宾补。有时 to be 可以省略。这类不定式改为被动语态后就变成了主语补足语。We believe her (to be) innocent.我们相信她无罪。I consider him (to be) a great man.我认为他
45、很伟大。She was considered (to be) too lazy.都认为她很懒。b. 感官动词如 feel, see, hear, watch, notice, observe, listen to, look at 等以及使役动词 make, have, let 等在跟不定式作宾语补足语时省略不定式符号 to。但在转换成被动语态时要加上 to。I heard him sing next door.我听见他在隔壁唱过歌。He was heard to sing next door.有人听见他在隔壁唱过歌。She made the boy go to bed early.她让那个男
46、孩早睡觉。The boy was made to go to bed early.那个男孩被迫早睡觉。c. 在动词 find 与 help 之后，不定式可以带 to 也可以不带 to。He was surprised to find the sheep (to) break the fence at this season.他发现羊在此季节越出羊栏，感到惊讶。I cant help you (to) do the house work. 我不能帮你做家务。（7）用作主语补足语不定式作主语补足语时，句子的主语是不定式的逻辑主语。He was considered to have finished
47、 the work.别人认为他已经完成了工作。He is said to be an artist.据说他是艺术家。4、动词不定式的否定式不定式的否定式由“not+动词不定式”构成。Tell him not to be late.告诉他不要迟到。The policeman told the boys not to play in the street.那位警察告诉那些男孩们不要在街上玩。5、动词不定式的复合结构（1）for+名词或代词 +不定式不定式的复合结构由“for+名词或代词+不定式”构成。这个名词或代词形式上是 for 的宾语，而意义上是不定式的逻辑主语。这种结构可在句子中作主语、宾语
48、、表语、定语、状语等。如：It is necessary for us to learn from each other.我们相互学习是必要的。（主语）I think it a good idea for her to study medicine.我认为她学医是个好主意。（宾语）The engine is for you to repair.这台发动机归你修。（表语）The lake is a good place for you to swim in.这湖是你游泳的好地方。（定语）I spoke slowly for them to make notes.我讲得很慢以便让他们作笔记。（状语
49、）（2） “It is + 形容词X 代词（名词）不定式” 句型 用 of 还是用 for 如果句中的形容词表示人物特征或品质，常同 of 搭配构成 “It is + 形容词of代词（名词）不定式”句型。如： bold ，brave, careful, careless, considerate, cruel, rude, generous, :right，wrong, kind，nice，good， polite，clever，wise， foolish, silly 等。这是一个带有感情色彩的不定式结构， 表示好意时，具有 “对 不胜感激”的意思；表示坏的意思时，含有“真是太 ，真是 透了 ”的意思。It is kind of you to help me.你帮助我真是太好了。It was foolish of us to do so.我们这样做真是太傻了。这一结构均可改为“主语be形容词不定式”但无感情色彩。You are kind to help.你帮我很好。We are foolish to do so.我们这样做傻。注意：在口语中，这一结构可由 how 引起， 表示强烈的感叹。这时，it is, it wa
