1、不定式不定式由“to+动词原形”构成,其否定形式是“not/never to do”,不定式可以带宾语或状语构成不定式短语,没有人称和数的变化,但有时态和语态的变化。不定式可以作主语、宾语、状语、表语和定语，但不能单独作谓语。不定式的逻辑主语有时用“for+名词或代词宾格” 构成。 结构:to do (否定)not/never to do二.时态与语态不定式 主动语态 被动语态一般式 to do to be done进行式 to be doing -完成式 to have done to have been done完成进行式 to have been doing -(1).They pret
2、ended not to see us.(一般式表示与谓语的动作同时/几乎/ 发生在它之后.)(2).He pretended to be sleeping.(在谓语动词发生的同时,不定式的动作也正在进行 )(3).She pretended to have known it before.(完成式表示动作发生在谓语动作之前)(4).Were happy to have been working with you.(完成进行式表示谓语动作发生之前,不定式的动作一直在进行而且可能之后也继续)1.作主语2.作宾语3.作宾语补足语4.作定语5.作状语6.作表语7.作独立成分8.与疑问词等连用三.用法
3、/功能(1).主语To see is to believe.Its important to learn English well. 单个不定式作主语时,谓语动词用单数 若不定式太长,往往用 it 作形式主语,不定式置后.(2).表语My job to help the patient.Your task to clean the classroom.(3)宾语I want to go home.The workers demanded to get better pay.I found it necessary to talk to him again.Think/consider/find
4、 it+adj.+to do常用动词不定式作宾语的动词有：hope, refuse, learn, set out ,choose, decide, agree, manage,pretend, plan. warn, tell, ask, force(4).宾补The teacher told me to clean the blackboard.I expect you to give me some help.五看 Watch,Observe,Notice,look at,see三使 Make,let,have 二听 Hear,listen to 一感觉:feelIs注意1help 后面
5、的“to”可省去e.g.They often help the grandma(to)carry water.2see,hear,watch,feel,notice,look at 等表示感觉和 let,make,have 等表示使役的动词后面，不定式作宾语时要省“to”（注：被动语态不省 to）e.g.I made him do his work. He was made to do his work(by me).3不定式用在介词 but,except,besides 后时,如果这些介词前有行为动词 do 的各种形式,那么介词后的不定式不带 to,相反则带 to.(1).She could
6、 do nothing but cry. (2).I have no choice but to go.(3).What do you like to do besides sleep.(5).定语I have something to say. He has a lot of homework to do.He is looking for a room to live in. There is nothing to worry about.(如果不定式中的动词是不及物动词,则不定式中要有介词.)请给我一支写字的笔.Please give me a pen to write with. 不定
7、式作定语时，应放在被修饰词的后面，而且放在其他后置定语之后。1.不定式做定语与所修饰的词之间有三种关系：(1)动宾关系 I have a lot of work to do.我有很多工作要做。(2)主谓关系 He is always the first to come.他总是第一个来。(3)同位关系 We all have a chance to go to college.我们都有上大学的机会。2.作定语的不定式如果是不及物动词，或者不定式所修饰的名词或代词是不定式动作的地点工具等，不定式后面须有相应的介词。e.g.He is looking for a room to live in.他在
8、找一个房间住。3.不定式所修饰的名词如果是 time,place 或 way，不定式后面的介词习惯上要省去。e.g.He had no money and no place to live.他没钱没地方住。4.something,anything,nothing,everything 等复合不定代词常用不定式做后置定语。e.g.Do you have anything to send?你有什么东西要寄吗(6)状语（表示目的或结果）I came here to see you He got up early to catch the train.在一些短语中也有体现in order to,so
9、as to,enough to,only to,too.to.,(7).独立结构To tell the truth,I dont agree with you.类似的结构 to be frank, to be honest,(8)不定式与疑问词 who,which,when,how,what 等连用，在句中起名词作用，可充当主语、表语、宾语等。He didnt know what to say.他不知道说什么。(宾语)How to solve the problem is very important.如何解决这个问题很重要。(主语)My question is when to start.我的问题是什么时候开始。 (表语)注意： 在与 why 连用时，只用于 why 或 why not 开头的简短疑问句中，后面紧跟的动词不定式不带 to。 Why not have a rest? 关于不定式中的小品词 to(1).不定式中的动词上文已出现过,下文要省略该动词.eg:Would you like to go with me?Id like to.(2).不定式是 to be 结构,be 不可省 .eg:Would you like to be a teacher?Id like to be.
