1、动词不定式用法动词不定式用法一、动词不定式的基本形式是“不定式符号 to+动词原形”，有时可以不带 to。动词不定式没有人称和数的变化。在句中不能单独作谓语，但仍保留动词的特性，可以有自己的宾语、 状语等。 动词不定式同它的宾语和状语一起构成不定式短语。例如：to sell flowers in the street在街上卖花to speak in the classroom在教室里讲话不定式省 to 有四种情况：1、使役动词 let, make, have 等后接不定式。例如：Let him go!The boss made the child labors work the whole n
2、ight.2、would rather, had better 后。例如：You had better stay at home.3、Why/Why not后。例如：Why not have a good rest on Sunday4、感官动词 see, watch, look at, hear, listen to, smell, feel, find，notice 等后作宾语补足语，省 to。例如：I saw him dance.注意：这些情况在被动语态中，不可省 to.例如：The child labors were made to work the whole night.二、动词不
3、定式具有名词、形容词和副词的特征，可以作句子的主语、表语、宾语、宾语补足语、定语和状语。1、用作主语直接把动词不定式置于句首的情况不多， 多数情况用 it 作形式主语， 把真正的主语动词不定式置于句末，特别是不定式短语较长时。动词不定式作主语，谓语动词用第三人称单数形式。带疑问词的不定式短语作主语常置于句首。例如：The head teacher said it was necessary to talk with his mother.How to make requests politely is important.2、用作表语动词不定式作表语，常用在 be 动词及 seem, appe
4、ar, happen 等词之后，构成系表结构。说明主语的内容、性质、特征。例如：The best way to improve your English is to join an English club.She seem to be well-known.3、用作宾语1. 用作宾语的动词不定式，常用在动词 ask, choose, agree，expect, hope, decide,learn， prefer, know， wish, want, would like / love 等及物动词之后， 构成动宾短语。例如：We decided to talk to some student
5、s about why they go there.He prefers to eat white bread and rice.Id love to visit Mexico.2.动词 feel, find, make, think, believe 等， 在语法上不能接受不定式作宾语， 只有用 it 作形式宾语，从而把动词不定式后置。句子结构是：主语feel / find / make/ . it+adj. / n.+to do.。例如：I find it difficult to remember everything.3.既可接动词不定式又可接 v-ing 形式作宾语，意思差别不大的动
6、词有 begin,start, like, love 等。一般说来，动词不定式表一次、数次的具体动作的全过程，v-ing 形式表习惯性的连续动作。但这种区别并不很严格，特别是美式英语，即使是习惯性的动作也可以用动词不定式。例如：Then I started to watch English-language TV.Im beginning to understand my Chinese roots, and who I am.（begin 用了进行时态，后面只接不定式作宾语，表示事情刚开始，还要继续下去。 ）4.后接动词不定式或 v-ing 形式作宾语， 意思差别较大的动词有 forget,
7、 remember等。后接不定式作宾语，表动作尚未发生；后接 v-ing 形式作宾语，表动作已经发生。stop to do 停下来做另外一件事，to do 是目的状语；stop doing 停止做、不做当前这件事，doing 是宾语。try to do 尽力做，try doing 试试看；go on to do 接着做另外的事，go on doing 继续做原来的事。例如：When I left home, I had forgotten to bring it with me.I stopped using them last year.5 后只接 v-ing 作宾语的一些常用特殊动词：gi
8、ve up, enjoy, practise, finish,mind 等。例如： Would you mind opening the window4、用作定语用作定语的动词不定式一般都位于被修饰的名词之后。例如：I have so much homework to do today.I cant think of any good advice to give her.通常 chance, place, time, way 等名词后接不定式作定语。另外在 the first, thesecond, the last, the only 等词后，也常用不定式作定语。例如：He needs t
9、ime to do homework.You want to know the best way to get around the city.5、用作补语1.常见动词不定式作宾语补足语的动词主要有：要求允许提议警告（ask, allow,permit, advise，warn） ，期望邀请鼓励（expect, suppose, invite, encourage） ，教导告诉想要（teach, tell, want） ，希望愿意（ wish, would like / love） 。例如：I invited her to have dinner at my house.Teenagers s
10、hould be allowed to choose their own clothes.2.动词不定式作补语，在主动语态句里不带 to，被动语态句里带 to 时多数动词是感官动词和使役动词，包括四“看”：look at, observe, see, watch，三“让”：have,let, make，二“听”：hear, listen to，一“感觉”：feel，一“注意”：notice。例如：This picture makes me feel tense！Of course we want to see Liu Yu achieve his dreams.后接动词不定式作补语，to 可带
11、可不带。一般说来，带 to 表间接帮助，不带 to表直接帮助。在被动语态句里，或者用不定式的否定式作补语时要带 to。例如： They can help you to compare two different products so that you can buy theone you really need.Using e-mail English helps you write quickly. said, be sure, happen, seem 等后面可以接带 to 的动词不定式作主语的补语。例如：He doesnt seem to have many friends.Be su
12、re not to miss them if they come to a city near you.6、用作状语1.目的状语，置于句首或句末，置于句首时常表示强调。为加强语气，常与 inorder 或 so as 组成短语。例如：Agroup of young people got together to discuss this question.In order to help him, we would do everything we can.注意：置于句首时只用 to do / in order to do。2.原因状语，多见于“sb.+be+adj.+to do.”结构句中。例
13、如：I was very sad to hear the news.On Monday he told a radio interviewer that he had run out of money to buy old bikes.3.结果状语，多见于“too.to”，“enough to.”结构句中。例如：Then Im too tired to do well.He is old enough to go to school .4.独立动词不定式多用作插入语， 表示说话人的心理状态或对事情的看法。例如：Id like to stay healthy, but to be honest,
14、 I only eat food that tastes good.To begin with, she spoke too quickly, and I couldnt understand every word.7、动词不定式的复合结构动词不定式的复合结构是“for / of sb. to do sth.”， for / of 引出不定式动作的逻辑主语。这种结构在句子中可以作主语、宾语、表语、定语、状语等。不定式复合结构的介词用 for 还是 of，主要决定于前面形容词的性质。一般说来，of 前面的形容词是 careful, clever, foolish, good, kind, nic
15、e, wise 等，既说明人的特性，又说明不定式动作的特性。for 前面的形容词是 dangerous, difficult, easy, hard, heavy,important, interesting, necessary 等，一般说明不定式动作的特性，不说明人的特性。前面如果是名词用 for。例如：Its also probably a good idea for parents to allow teenagers to study in groupsduring the evening.Its kind of you to help me.8、带疑问词的不定式短语动词不定式前面可
16、以带疑问代词 what, which, who 或疑问副词 how, when, where,why 等。这种结构起名词的作用，在句子里用作宾语、主语、表语等，或者单独使用。要注意的是，why 后面的不定式不带 to。例如：I dont know what to try next. （作宾语）Where to go is not decided yet.（作主语）注意：单独使用时相当于一个特殊疑问句。What to do next(=What will we / you do next)Why go there(=Why do we / you go there)9、动词不定式的否定式不定式的
17、否定式是not / never to do.， 不带to的不定式的否定式是not / never do.例如：Sometimes they have disagreements, and decide not to talk to each other.His parents tell him never to drive after drinking.巩固练习：1、He read the instruction to find out how _ the computer.A. useB. to useC. usingD. uses2、There are some dangerous fis
18、hes in this river, and Ive warned Jack _here.to swimB .to not swimC. swim not toD. to swim not3、The article said that he hoped _ drawing the picture soon.son to finishfinishC. finishD. his son will finish4、Listen! Can you hear a baby _cryD. cries5、 “Dont always make Michael _ this or that. He is alr
19、eady a big boy,dear,”Bushsaid to his wife.do6、Dont forget _ the letter.A. to send7、John was made _the car for a week as a punishment.wash8、Thank you very much _ the present.give megiving meme9、I have noyou give me a piece of paper _write ininwrite on10、The teacher got his students _ the top of the mountain.reach11、 If everyone makes a contribution to _ the environment,the world will becomemuch more beautiful.12、Tracy cant play the match_ instead.Lily doLily to do itLily to do it13、We lock the door to keep the books _ .be stolenbeing stolenstealing14、On my way home, I stopped _ some food.buy
