1、动词不定式及其用法Grammar一动词不定式动词不定式由“to+动词原形(do)”构成，其中to不是介词，而是动词不定式的符号，动词不定式没有人称和数的变化。Todo在句中作主语、宾语、表语、定语、状语、补足语等,但不能作谓语。作主语To be a doctoris hard.To learn English wellis not easy.1.做医生很难。2.学好英语不容易。It is hardto be a doctor.It is not easyto learn English well.1.It’s goodfor usto read English inthe
2、 morning.2.It is importantfor studentsto useEnglish every day.总结：如果知道动词不定式的动作是谁做的，可以在动词不定式前面加一个由介词for引导的短语，称为不定式的复合结构。作表语MyjobistoteachEnglish.Toseeistobelieve.1.我的工作是教英语。2.眼见为实。动词不定式（短语）作表语常用于系词be的后面。作宾语They beginto workat eight every morning.Shewantstohaveapicnic.1.他们每天早晨8点开始工作。2.她想要去野餐。
3、动词不定式（短语）可以放在一些动词后面用作宾语。注意：（1）如果and连接两个动词不定式，第二个动词不定式一般省“to”1.He wants to go and have a swim with us.（2）若作宾语的动词不定式（短语）很长，可用it作形式宾语，把不定式后移。I finditinterestingto learn English with you.能以动词不定式作宾语的动词有：begin,decide,agree,offer,refuse,start, want, forget, remember,show, learn, like, hate, love,
4、 ask等。Remember!e.g.wecan’tafford___________(pay)forsuchabighouse.tobuy作宾补Sheaskedmetostaythere.1.她叫我呆在这儿。2.请允许我介绍Mr.White给你们。PleaseallowmetointroduceMr.Whitetoyou.1.不可以省to的不定式作宾语补足语：tell/ask/want/would like/wish/like/invite/encourage/teach/allowsb. to do sth.如:Hedidn’tallowus_______(smoke)
5、inhishouse.tosmoke2.省“to”的不定式作宾语补足语：1)Let / make / have sb. do sth.Letthe boygoout now.2)see / watch / hear / notice / feel sb. do sth.Isawthe studentsplaybasketball yesterday.3)would rather，had better句型后4)Why… / why not…句型后5）but和except后。but前是实义动词do时，后面出现的不定式不带to。比较：He wants to do nothing
6、but go out.他只想出去玩。He wants to believe anything but to takethe medicine.除了吃这药，他什么都信。1.如果上述结构变为被动语态,原来不带to的不定式要加to。如:Isawhimgoupstairs.Hewasseentogoupstairs.有人看见他上楼去了。Becareful!注意1:2.带to的否定式是直接在to之前加not.Tell them not to play football in the street.3.省to的动词不定式的否定式是直接在动词前面加not.Let the boy not
7、go.注意2作定语Doyouhaveanythingtosay?1.你有什么要说的吗?2.她没有纸写字。She has no paperto write on.动词不定式作定语常用来修饰名词或不定代词，放于所修饰的词后，为后置定语。Itseemsthathehasnopen______. A.towriteB.towritewith C.writingD.writingwith注意如果作定语的不定式是不及物动词，其后应加上必要的介词E.g.He has no house tolive in.他没有房子住。不定式作定
