高中英语语法不定式

动词不定式考点（The Infinitive）定义：动词不定式是非谓语动词的一种，它没有人称和数的变化，在句子中不能独立作谓语，但它仍保持动词的特点，既可以有自己的宾语和状语。

E.g. He wants his students to read the book aloud.A．基本形式主动形式被动形式一般式to do to be done完成式to have done to have been done 进行式to be doing 无完成进行式to have been doing 无2不定式的意义不定式的一般式(to do )一般式表示的动作或状态，发生在谓语动词表示的动作或状态的同时或之后。

当不定式的逻辑主语是这个不定式所表示的动作的承受者时,不定式一般要用被动式(to be done).eg: My wish is to become a doctorHe seemed to be tired.She stopped to have a rest.The building to be finished next month is for our teachers.I am going to Beijing, I have something to take to my parents, do youhave something to be taken to your parents?不定式的进行式（to be doing）如果谓语表示的动作(情况)发生时, 不定式表示动作正在进行,这时候不定式就要用进行式.eg: They are said to be building another bridge across the street.They seemed to be talking about something important.When I went to his home, he happened to be traveling around the world.I’m glad to be working with you.不定式的完成式 (to have done)如果不定式所表示的动作或状态发生在谓语动词所表示动作或状态之前，就用完成式；若是在此基础上的被动含义，就用完成被动式( to have been done).eg:He is said to have written a novel about the Long March.He thought it a pity not to have invited us.The assistant seemed to have been fired.He is said to have been taught French when he was a child.Einstein is said to have built up his theory when he was in his twenties.不定式的完成进行式(to have been doing)如果不定式的动作是在谓语所表示的时间之前一直在进行或有可能继续进行的动作，就要用完成进行式.eg: They are said to have been collecting folk songs in Xinjiang.We’re happy to have been working with the experts all the month.B. 用法：由于动词不定式具有名次、形容词、和副词的特征，所以它在句中可作主语、表语、宾语、定语和状语。

一、不定式作主语：1、不定式作主语时，常可以改成动名词，如To ask him for help is necessary.= Asking him for help is necessary.To see is to believe.2、（1）it 为形式主语的句型：It took (us) two hours to get there by bike.(2) 在一些形容事物性质的形容词（necessary, hard, difficult, possible, unusual, normal, suitable, proper, appropriate等）句型中，动词不定式的复合结构为for sb. to do , 如：It is important for us to take part in physical labor.(3)在一些形容人的品性的形容词（polite, rude, kind, friendly, wrong, clever, wise, stupid, silly, foolish等）句型中，动词不定式的复合结构为of sb. to do, 如It was stupid of her to make such a mistake.注意：1)不定式作主语时,谓语用单数2)it形式主语。

当主语较长，谓语较短时，常用it做形式主语，而将不定式放到谓语的后面。

3）主系表结构To see is to believe.二、不定式作表语：1、主语多用aim duty hope idea intention plan job suggestion wish purpose task 等抽象名词或以 what 引导的名词性从句表示，后面的不定式说明其内容, 不定式作表语常表示将来的动作或状态。

eg: My idea is to climb the mountain from the north.What I would suggest is to start work at once.My wish is to be a scientist.The main thing is to keep our room clean.2、不定式作表语时，常可以改成动名词，如The great happiness is to serve the people.= The great happiness is serving the people.三、不定式作宾语1、接不定式作宾语的动词及短语：manege, decide, choose, learn, pretend, afford, offer, fail, hesitate, arrange, plan, intend, tend, aim, attempt, happen, help, agree, want, ask, promise, expect, wish, demand, long, would/should like, take steps/measures/action, make up one’s mind, try one’s best, do one’s utmost, be determined/make efforts/spare no effort, take pains/trouble, go al theway/go out of one’s way, 如He pretended to be listening attentively2、I thought it an honor to have been invited to the party. (it 为形式宾语，不定式的完成被动式）3、He gave us some advice on how to learn English. (不定式作介词的宾语）*注意:1某些及物动词可用-ing也可用动词不定式作宾语但意义不同stop go on remember forget regret try mean can’t helpbe used to2某些及物动词think,believe,consider,feel,find,make等后常用it作形式宾语e.g Technology makes it possible to realize our dream.四、不定式作定语1、“have”, “there be”, “with”表示有某是要去做，后面的名词常用不定式结构作定语，如：Have you got anything to say?With nothing to do, he went home.There is nothing (for us) to think about.2、以不定式作定语修饰含有序数词的名词，又是序数词后的名词可省略，如：She was the first (person)to think of the idea.3、一些名词（right, chance, opportunity, ability, plan, attempt, wish, desire等）常用不定式作定语，如：In the past,women had no right to vote.I’d like to have a chance to see more of him.This will be a good opportunity to exchange experience.4、当动词与不定式搭配时，其名词形式后的定语一般也用不定式，这类词主要有：plan, promise, desire, refuse, decide, agree, attempt, tempt, wish, fail等，如：（1）They planned to go abroad.They made some changes in their plan to go abroad.(2) He failed to carry out his promise.His failure to get their support led to his resignation.5、当形容词与不定式搭配时，其名词形式后的定语一般用不定式，这类词主要有：willing, ready, anxious, eager, able, ambitious等，如：（1）He is willing to help people in need.I’m impressed by his willingness to help people.(2) He isn’t courageous enough to ask for help.I had not the courage to tell you.五、不定式作状语1、不定式作状语时，主要表示“目的”，如：To/In order to pass the university entrance examination, he works deep into night.(句首可用To/In order to)He works deep into night to/in order to/so as to pass the university entrance examination.(句中可用to/in order to/so as to)2、不定式作状语时，也可表“结果”，如：（1）下列固定结构中用不定式表结果：The problem is too difficult (for me) to work out.He was so angry as to be unable to speak.The ice is thick enough to walk on.（2）不定式表预料外的结果，常用only或never放在不定式前表强调，如：I visited him (only) to find him out.After that day they were separated, never to see each other again.3、形容词后不定式表原因，这类词主要有：glad, gappy, eager, anxious, sorry, sad, surprised, astonish, amazed等，如：They were very sad to hear the news.六、不定式作补足语Ask, tell, order, request, require, persuade, urge, invite, remind, inspire, encourage, warn, cause, force, enable, advise, recommend, permit, allow, forbid, wish, expect, command等动词后常接不定式作宾补，如：Tom’s parents often warn him not to fall into bad company. (warn sb. Not to do sth. 警告某人别做某事)Remind me to give you Tracy’s number before you go. ( remind sb to do sth.提醒某人做某事) [注1] 如果谓语动词为感官动词或使役动词，则作宾补的不定式不可带to，这些动词有see, hear, feel, watch, notice; have, make, let等。