不定式由“to+动词原形”构成,其否定形式是“not/nevertodo”,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/of+名词或代词宾格”构成。不定式todo壹.结构:todo(否定)not/nevertodo二.时态与语态主动语态主动语态被动语态被动语态一般式一般式进行式进行式完成式完成式完成进行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)TospeakmoreisthebestwaytoTospeakmoreisthebestwaytolearnalanguage.learnalanguage.HehopedtoimprovehisEnglish.HehopedtoimprovehisEnglish.Heaskedhismothertoleave.Heaskedhismothertoleave.Hewakedupearlytocatchthe1stHewakedupearlytocatchthe1sttrain.train.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’simportanttolearnEnglishwell.(1).主语•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.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.afford,agree,appear,arrange,ask,afford,agree,appear,arrange,ask,attempt,care,choose,claim,come,attempt,care,choose,claim,come,dare,decide,demand,deserve,dare,decide,demand,deserve,determine,elect,determine,elect,Thefollowingverbsarenormallyfollowedbytheinfinitive.expect,fail,get,guarantee,hate,helexpect,fail,get,guarantee,hate,help,hesitatep,hesitate，，hope,hurry,intend,lehope,hurry,intend,learn,long,manage,mean,need,offer,arn,long,manage,mean,need,offer,plan,prepare,pretend,promiseplan,prepare,pretend,promise，，rrefuse,say,seem,tend,threaten,waefuse,say,seem,tend,threaten,want,wishnt,wishThefollowingverbsarenormallyfollowedbyV-ing.avoid,consider,delay,deny,dislike,avoid,consider,delay,deny,dislike,endure,enjoy,escape,forgive,finish,endure,enjoy,escape,forgive,finish,imagine,keep,mind,miss,pardon,pimagine,keep,mind,miss,pardon,prevent,resist,suggest,understand,crevent,resist,suggest,understand,can’thelpan’thelpThefollowingverbsarenormallyfollowedbyV-ingortheinfinitive.love,like,hate,prefer,dislike,begin,colove,like,hate,prefer,dislike,begin,continue,intend,attempt,propose,want,ntinue,intend,attempt,propose,want,need,remember,forget,regret,try,desneed,remember,forget,regret,try,deserve,starterve,startTheteachertoldmetocleantheblackboard.Iexpectyoutogivemesomehelp.(4).宾补五看watchseelookatobservenotice三使letmakehave二听listentohear一感觉:feele.g.Imadehimdohiswork.Hewasmadetodohiswork(byme).注意1>help后面的“to”可省去e.g.Theyoftenhelpthegrandma(to)carrywater.2>see,hear,watch,feel,notice,lookat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）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).Shecoulddonothingbutcry.(2)....
