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 lear n from your frie nds is importa nt.=lt is importa nt to lear n from your frie nds . ______ To leave without say ing goodbye is impolite.= It is impolite to leave without saying ________ goodbye.To chat with Miss White is a pleasa nt thi ng.=lt is a pleasa nt thi ng to chat with Miss ______ White.To walk to school takes me ten minu tes.=lt takes me ten minu tes to walk to school. _______ 句型总结It is + adj. + of sb. to do sb：・i= are +adj. +to do 在以某些表示人的品质、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 himto speak to old people like that.It is + adj. + for sb. to do …乞aisb+Odj. +to do 女:果要说明不定式表示的动作是谁做的，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 n ecessary for us to study hard ___It is easy for him to speak En glish.动词不定式作主语练习1. It's our duty the room every day.A. to clea nB. clea nedC. clea nD. cleans（甘肃省）2. It's hard for us En glish well.A. learnB. lear nsC. to lear nD. 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 policema n.My job is to help the patie nt.Your task is to clea n the classroom.My dream is to own a robot.The doctor ' s suggesti o nase more exercise.The best way is to talk to your pare nts.His pla n 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）彳艮多，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, man age, prete nd,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 wan ted to borrow my CD player.I hope to speak En glish well.The workers demanded to get better pay .I hope to hear from you soon.Joh n does n wa n t to be the host of the charity show.They are trying to solve the problem by himself.Millio ns 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 doi ng 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 n eed to do sth.需要做某事 need doi ng sth. 需要被做Don ' t forgfeo turn off the lights before leaving. Father must stop smok ing.This bike n eeds repairi ng/me nding.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 lear n En glish. I fond it difficult to lear n 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 pare nts did n ' 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. Gree n 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 tblo his work.. ---------------------- Please liste n to me to_s ing this song aga in.In ternet bars must n'lett an ybody watch bad thin gs, especially childre n. --------------- l etsb.do sth.He ofte n helps （to ） clea n the room.Mr. Zhang always helps us （to ） learn English.make sb.do sth.liste n to sb.do sth. n my door. ------------------- The boss made the girl to w°rk ten hour a day. You must watch me tdlo everything --------------I felt some one tofeel sb.do sth. make sb.do sth.watch sb.do sth.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 n ext room.Joh n was made to wash the car for a week as a puni shme nt.The patie nt was warned not to eat food after the operati on.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 whe n 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 ofte n asks us _____ his Chin ese, so his Chin ese is much better tha n before.A. help himB. to help him withC. to help withD. helps him with （江苏省）5. Mr Li ofte n teaches his Japa nese friends ____ Chin ese food.A. cookB. cooksC. to cookD. cooked （甘肃省）6. We saw him _ the buildi ng 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. feeli ngD. feel8. Your father is sleep ing. 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 after noon.A. doB. doi ngC. 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。