语法：动词不定式动词不定动式是一种非谓语动词形式，它没有人称和数的变化，在句子中不能作谓语，但可以作除谓语之外的其它任何句子成分（主语、表语、宾语、宾语补足语、定语和状语）；动词不定式具有名词、形容词和副词的特征，同时还保持动词的某些特点，既可以有自己的宾语和状语，动词不定式和它的宾语和状语构成不定式短语。
一、构成：to do .否定式not to do二、常见时态：一般时to do 进行时to be doing 完成式to have done完成进行式to have been doing三、动词不定式在句子中的成分1、作句子的主语：现实中常用it作形式主语，而把真正的主语动词不定式（或短语）后置。
比较下列句子To learn from your friends is important.=It is important to learn from your friends .To leave without saying goodbye is impolite.= It is impolite to leave without sayinggoodbye.To chat with Miss White is a pleasant thing.=It is a pleasant thing to chat with MissWhite.To walk to school takes me ten minutes.=It takes me ten minutes to walk to school.句型总结在以某些表示人的品质、sb. is are +adj. +to do…It is + adj. + of sb. to do…=特征等的形容词（如kind、good、nice、wrong、clever、right等）作表语时，不定式之前常加一个引起的短语，说明不定式指的是谁的情况（可以理解为某人的好，坏，聪明，愚蠢，对，错等等）。
It is very kind of you to help me.It’s not polite of him to speak to old people like that.如果要说明不定式表示的are +adj. +to do…It is + adj. + for sb. to do…≠ sb. is动作是谁做的，则在不定式前加一个for引起的短语，即不定式的逻辑主语。
It is necessary for us to study hard.It is easy for him to speak English.动词不定式作主语练习1. It's our duty _________ the room every day.A. to cleanB. cleanedC. cleanD. cleans(甘肃省)2. It's hard for us _____ English well.A. learnB. learnsC. to learnD. learning(江西省)3.建造这座立交桥将花费工人们一年多的时间。
It will ______the workers over a year _____ ____the flyover.(北京市海淀区)4. It's very nice _____you to get me two tickets _________ the World Cup.A. for，ofB. of，forC. to，forD. of，to(安徽省)KEYS: 1. A 2.C 3. take, to build 4. B2、作句子的表语：不定式放在be 动词后面，用作表语如：Her dream is to be a policeman.My job is to help the patient.Your task is to clean the classroom.My dream is to own a robot.to take more exercise.The doctor’s suggestion isThe best way is to talk to your parents.His plan is to travel to Beijing this summer.My purpose is to help you solve this problem.3、作句子的宾语：不定式放在及物动词后，用作宾语。
能跟不定式作宾语的动词（及物）很多，常见的有want, like, hate, wish, hope, prefer, try, ask, start, begin, decide, learn,choose, agree, expect, remember, forget, plan, decide, would like, need, choose, agree, promise, refuse, set out, manage, pretend,I want to go home.The workers demanded to get better pay.They began to read and write.She forgot to close the door.He wanted to borrow my CD player.I hope to speak English well.The workers demanded to get better pay.I hope to hear from you soon.John doesn’twant to be the host of the charity show.They are trying to solve the problem by himself.Millions of people have learned to use computers.有些动词既可跟不定式作宾语，也可跟动名词作宾语，但含义不同：forget to do sth.忘记要做某事forget doing sth.忘记曾经做过某事stop to do sth. 停下来去做某事stop doing sth.停止做某事go on to do sth.继续做另一件事go on doing sth.继续做原来在做的事need to do sth.需要做某事need doing sth. 需要被做Don’t forge to turn off the lights before leaving.Father must stop smoking.This bike needs repairing/mending.注意1：动词不定式作宾语时如带有宾语补足语，则要把不定式放在后面，用it作形式主语，构成“主语+动词+it+宾补（形容词、名词）+不定式”结构I found it necessary to talk to him again.I found it important to learn English.I fond it difficult to learn physics.注意2：常用带to的动词不定式作宾语补足语的动词有want, ask, tell, order, get, wish, allow, invite, teach, encourage, beg, 等。
构成“vt,+sb.+(not)to do sth.”结构。
The teacher told us to read the text.He asked me not to tell you the news.His parents didn’t allow him to play.I expect you to give me some help.Mr.Lu asks ue to hand in our homework on time.The docter advised Mr. Green to drink more water.Mr. Wu tells the students not to shout in class.Mrs. Read whishes her son to learn English well.注意3：不定式作宾补省去 to 的情况(在被动语态中则to 不能省掉)常用省去to的动词不定式作补足语的动词有：一感（feel）、二听（hear, listen to）、三让（make, let, have）、四看（look at, see, watch, notice, observe）、半帮助help（可带to，也可不带to help sb (to) do sth）I made him to do his work. .----------------------------make sb.do sth.Please listen to me to sing this song again.-------------------listen to sb.do sth.I felt someone to open my door.--------------------------------feel sb.do sth.The boss made the girl to work ten hour a day.-------------make sb.do sth.You must watch me to do everything--------------------------watch sb.do sth.let anybody watch bad things, especially children.-------let Internet bars mustn’tsb.do sth.He often helps (to) clean the room.Mr. Zhang always helps us (to) learn English.被动语to要加上He was made to do his work (by me)They are made to work for 12 hours a day.He was heard to speak in the next room.John was made to wash the car for a week as a punishment.The patient was warned not to eat food after the operation.Intern et bars mustn’t let anybody watch bad things, especially children.动词不定式作宾语练习1.He wants ___ some vegetables.A. buyB. buyingC. to buyD. buys (山西省)2.Don't forget ______ your homework with you when you come to school.A. to bringB. bringingC. to takeD. taking (福建省)3.He found it very difficult ___A.sleepingB. sleepsC. sleptD. to fall asleep (湖南省)4. Robert often asks us ______ his Chinese, so his Chinese is much better than before.A. help himB. to help him withC. to help withD. helps him with (江苏省)5. Mr Li often teaches his Japanese friends ______ Chinese food.A. cookB. cooksC. to cookD. cooked (甘肃省)6. We saw him ___the building and go upstairs.A. to enterB. enterC. enteringD. entered (河南省)7. So much work usually makes them __very tired.A. to feelB. feelsC. feelingD. feel8. Your father is sleeping. You'd better ______.A. not wake up himB. not to wake up himC. not wake him upD. not to wake him up (陕西省)9. I was made ___ my homework in the afternoon.A. doB. doingC. to doD. didKeys： 1. C 2. A 3. D 4.B 5. C 6. B 7. D 8. C 9. C4、作句子的定语：不定式作定语时，应放在被修饰词的后面作后置定语。
