一.结构:todo(否定)nottodo二.时态与语态主动语态被动语态一般式进行式完成式完成进行式不定式todotobedonetobedoingtohavedonetohavebeendonetohavebeendoing--------------------(1).Theypretendednottoseeus.(2).Hepretendedtobesleeping.(3).Shepretendedtohaveknownitbefore.(一般式表示与谓语的动作同时/几乎/发生在它之后.)(在谓语动词发生的同时,不定式的动作也正在进行)(完成式表示动作发生在谓语动作之前)(4).We’rehappytohavebeenworkingwithyou.(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/功能Toseeistobelieve.It’simportanttolearn.(1).主语不定式作主语时,往往放在谓语之后,用it作形式主语.Myjobtohelpthepatient.Yourtasktocleantheclassroom.isis(2).表语Iwanttogohome.Theworkersdemandedtogetbetterpay.Ifounditnecessarytotalktohimagain.(3)宾语think/consider/findit+adj.+todo常用动词不定式作宾语的动词有:hope,refuse,learn,setoutchoose,decide,agree,manage,pretend,plan.Theteachertoldmetocleantheblackboard.Iexpectyoutogivemesomehelp.(4).宾补warn,tell,allow,help,ask,force等一感:feel二听:hearlistento三使:makelethave四看:noticeseeobservewatch半帮助:helpImadehimdohiswork.Hewasmadetodohiswork(byme).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).Shecoulddonothingbutcry.(2).Ihavenochoicebuttogo.(3).Whatdoyouliketodobesidessleep.Ihavesomethingtosay.Hehasalotofhomeworktodo.Heislookingforaroomtolivein.Thereisnothingtoworryabout.(5).定语(如果不定式中的动词是不及物动词,则不定式中要有介词.)不定式所修饰的名词或代词是不定式动作的地点工具等,即使是及物动词,不定式后面仍须有相应的介词。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。Hehadnomoneyandnoplacetolive.他没钱没地方住。请给我一支写字的笔.Pleasegivemeapentowritewith.something,anything,nothing,everything等复合不定代词常用不定式做后置定语。注意比较:1.Doyouhaveanythingtosend?你有什么东西要寄吗?(不定式tosend的动作执行者是you)2.Doyouhaveanythingtobesent?你有什么要(我或别人)寄的东西吗?(不定式tobesent的动作执行者是已被省略的me或someoneelse)Icameheretoseeyou.Hegotupearlytocatchthetrain.(6)状语inorderto,soasto,enoughto,onlyto,too….to.,(7).独立结构•tobefrank,•tobehonest,•totellthetruthTotellthetruth,Idon’tagreewithyou.(1).不定式中的动词上文已出现过,下文要省略该动词.eg:Wouldyouliketogowithme?I’dliketo.(2).不定式是tobe结构,be不可省.eg:Wouldyouliketobeateacher?I’dliketobe.•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。Hedidn’tknowwhattosay.他不知道说什么。(宾语)Howtosolvetheproblemisveryimportant.如何解决这个问题很重要。(主语)Myquestioniswhentostart.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whynot开头的简短疑问句中,后面紧跟的动词不定式不带to。Whynothavearest?