TheInfinitive动词不定式动词不定式的构成:肯定式:to+动词原形否定式:notto+动词原形复合结构:forsb.todo动词不定式的用法动词不定式可充当的句子成分:主语宾语定语表语状语宾语补足语注:动词不定式不能作谓语A.不定式作主语(一定要带to,谓语动词要用单数)Toplayvideogameisfun.TolearnEnglishwellisimportant.不定式作主语时,常用it作形式主语,而将真正的主语即动词不定式放在句末,构成固定句型。•Itis+n.(+forsb.)+todosth.用于此句型的名词有:pity,shame,pleasure,one’sduty,one’sjob,fun,joy,goodmanners,badmanners等。•Ittakessb.+sometime+todosth.该句型意为“做某事花费某人多长时间”。•It’s+adj.+(for/ofsb.)+todosth.该句型意为“做某事对某人来说是……”。不定式作主语的常用句型:1.It’scleverofyoutorefuseher.2.Itwascarelessofhertomakesuchamistake.3.It‘sverykindofyoutohelpus.1.It‘snecessaryforyoutogiveupsmoking.2.It‘seasyformetodothat.3.It‘sveryhardforhimtostudytwolanguages.形容词为描述人的品质的词,使用of。(形容词修饰不定式时用介词for.形容词修饰逻辑主语时用介词of.)good,kind,nice,clever,foolish,right,honest,careful,polite,wrong,bad,foolish,careless。forsb./ofsb.的区别用介词后面的代词作主语,用介词前边的形容词作表语,造个句子。如果道理上通顺用of,不通则用for。1.It’sveryniceofyoutosayso.→Youarenice.(通顺,所以应用of)2.It’shardforhimtofinishtheprojectbyhimself→Heishard.(人是困难的,不通,因此应用for)不定式像名词一样,可以放在be动词后面。1.MywishistovisitLondonnextyear.2.Tom’sideaistogotoForestParktohaveapicnic.3.Theimportantthingistosavelives.4.Mywishistowriteagoodbookforchildren.5.Ourworkistobuildthehighway.6.MyjobistoteachEnglish.7.Myideaistoclimbthemountainfromthenorth.8.Mysuggestionistostartworkatonce.B.不定式作表语one’swish/job/aim/goal/ambition/plan/dream/way/work/hope/duty/idea/suggestionistodo/be…(1)Ihopetobeadoctor.(2)Shedecidedtomakeanothertry.(3)Theyallwanttoseethefilm.(4)Wehopetobebackhomeat6:00.(5)Freddidn’thaveanymoney,sohedecidedtolookforajob.常见的能跟带to不定式的动词及短语:want/wish/hope/decide/learn/plan/wouldlike/getreadytodo…C.不定式作宾语e.g.Ifinditdifficulttounderstandhim.Wethoughtitwrongnottohelpher.Theyfounditimpossibletogeteverythingreadyintime.it作形式宾语,而将真正的宾语动词不定式置于句末。sb.believe/think/consider/feel/make/find+it+adj.+todosth.1.Idon’tknowwheretogo.2.Hedidn’tknowwhattodo./howtodoit.3.Canyoutellmehowtogetthere?4.Ican’tdecidewhichtochoose.5.Theteachershowedushowtouseacomputer.“疑问词+不定式”结构可以转换为从句形式1)Idon’tknowwhereIwillgo.2)Hedidn’tknowwhathewoulddo/howhecoulddoit.3)CanyoutellmehowIcangetthere.4)Ican’tdecidewhichIwillchoose.5)Theteachershowedushowwecoulduseacomputer.不定式与疑问词连用,构成不定式短语,作宾语1.Wehavecometolearnfromyou.2.Igotupearlytocatchthebus.3.Theboyisoldenoughtogotoschool.4.Hewastooexcitedtosayaword.5.Shewassurprisedtohearthenews.6.I’mgladtomeetyou.D.不定式作状语不定式结构可以作状语,修饰动词、形容词、副词等,表示目的、原因、结果等。表示目的表示原因表示结果表示目的:Hecameherejusttoaskmesomequestions.Heboughtabicycletogototownmorequickly.Hewenthometoseehismother.HecamehereinordertoseeCharlie.Heshoutedandwavedsoastobenoticed.Hewentearlyinordernottomissthetrain.Iturnedtheradiodownsoasnottodisturbhim.为了强调表示目的的不定式结构,通常可以用inorder(not)to或soas(not)to(soasto不能放在句首)可以和sothat引导的目的状语从句转换。MrLigotupearlysoththecouldcatchtheearlybus.→MrLigotupearlysoas/inordertocatchtheearlybus.表示结果:一般用在enoughto,too…to等结构中,可以和so…that引导的结果状语从句转换1.Heranfastenoughtocatchupwiththem.2.Heistooyoungtogotoschool.3.Shewastooexcitedtosayaword.Heransofastthathecaughtupwiththem.Heissoyoungthathecan’tgotoschool.Heisn’toldenoughtogotoschool.Shewassoexcitedthatshecouldn’tsayaword.表示原因:be+adj(glad.sorry.sure.happy.afraid.surprised等表情感的形容词后)+todosth.下列动词用不定式作宾语补足语时,带to:ask/tell/order/want/invite/allow/like/warn/encourage/teachwouldlikesbtodo…1.Mymotheralwayslikesmetogetupearly.2.LucyoftenteachesmetolearnEnglish.3.Shedoesn’twanthertoattendthemeeting.4.Iaskedhimtoshowmethenewdictionary.5.Sheaskedmetostaythere.6.PleaseallowmetointroduceMr.Whitetoyou.E.不定式作宾语补足语下列动词用不定式作宾语补足语时,必须省去不定式符号to:e.g.1.Heobservedsomeoneopenthedoor.2.Iwatchedthemgetintothecar.3.Didyounoticehimleavetheroom?学会记忆:作宾补不带to.一感:feel二听:hear,listento三使役/让:let,make,have五看:see,watch,lookat,observe,notice可带可不带to:help总结:省to的不定式1)情态动词(除ought外,oughtto):2)使役动词let,have,make3)感官动词see,watch,lookat,notice,observe,hear,listento,smell,feel,find等后作宾补,省略to。4)wouldrather,hadbetter5)Whydon’tyou…/whynot…:6)help可带to,也可不带to,helpsb.(to)dosth.7)hadbetter(not)8)Will/Wouldyouplease…?1.Ihavealotofhomeworktodo.2.Doyouhaveanythingtosay?3.Myfatherhassomethingimportanttotellme.4.Wouldyoulikesomethingtodrink?5.Hereisabookforyoutoread.6.Ihavenotimetotalkwithher.7.Heneedsaroomtolivein.8.Hewasalwaysthelasttoleave.9.Bettywasthefirsttoknowthetruth.10.Sheusuallyhasalotofmeetingstoattendintheevening.11.Iwanttogetsomethingtoreadduringthevocation.F.不定式作定语不定式作定语时,通常总是以短语的形式在句中出现的,因此作定语时要放在它所修饰的名词或代词之后。不定式与所修饰的词构成动宾关系时,如果不定式是不及物动词,它后面应加上相应的介词1.Thenursehasfivechildrentolookafter.2.Let’sfirstfindaroomtoputthethingsin.3.Pleasepassmesomepapertowriteon.4.There’snothingforustoworryabout.5.Shehasanicepentowritewith.6.Heboughtaflatforthefamilytolivein.e.g.Heistheonlypersontoknowthetruth.Sheisalwaysthefirsttocomeandthelasttoleave.当名词被thefirst,thelast,theonly等序数词以及形容词最高级修饰时,常用不定式作定语。thefirst,thelast,thenext,theonlytodosth注意作简短回答或避免不必要的重复时,动词不定式常常省去to后面的动词,只保留to。A:Wouldyouliketocometomyparty?Marywantedtousemybike,butIaskedhernotto(usemybike).B:Yes,I’dloveto(cometoyourparty).Ex:1.Todothatsortofthingisfoolish.2.Iwanttoseeyouthisevening.3.Theworkyouhavetodonowistofinishitqu