动词不定式讲解

1/7一动词不定式：to+动词原形1.基本用法：可在句中作主、宾、表、定、状、补。1)作主语Togetupearlyisagoodhabit.It'ssonicetohearyourvoice.(it为形式主语)ItisimportantforustolearnEnglishwell.It’ssillyofyoutodosuchathing.HowtoimproveourEnglishisstillaproblem.2)作宾语Weallhopetoseeyou.TheyfoundithardtolearnChinese.(it为形式宾语)Idonotknowwhattodonext.(疑问词+不定式)HeaskedmehowtoimproveEnglish.(疑问词+不定式)3)作表语①一般情况Myworkistocleantheroomeveryday.Hisdreamistobeadoctor.Thequestionishowtoputitintopractice.问题是怎样把它付诸实施。Heseemedtohaveknownthenews.②如果主语是不定式，则表语也用不定式。例如：Toseeistobelieve.Seeingisbelieving.③作表语的不定式有时可省略符号to：这时主语部分必须含有动词do,而作表语的不定式AllIdidwas(to)givehimalittlehelp.Whatwewanttodonowis(to)havearest.4)作定语①不定式作定语时，被修饰的名词常为它的逻辑宾语。不定式与该名词存在逻辑上的动宾Ihavesomeclothestowash.(后置定语)2/7Hehassomethingimportanttotellyou.如果不定式是不及物动词，后面应有必要的介词。Givemeapentowritewith.Ineedawarmroomtolivein.②逻辑上的主谓关系。Hewasthefirstteachertocome.Ineedaboxtoholdmybooks.Isthereanyonetoanswermyquestion?Hewasthelaststudenttohavelefttheclassroom.(不定式完成式)③逻辑上的同位关系。Everyonehastherighttospeakatthemeeting=Everyonehastherightthathemay/canspeakatthemeeting.Dokeepyourpromisetowritetome.=Dokeepyourpromisethatyouwillwritetome.5)作状语①作目的状语Hewillgotothestationtomeethisfriend.IoftenreadChinaDailyinorderto(或soasto)improvemyEnglish.(inorderto可放在Icomehereonlytosaygood-byetoyou.②作结果状语Ihurriedtohishouseonlytofindhewasout.Heis(not)oldenoughtojointhearmy.It’stoolatetoplaybasketball.Hewassoangryastobeunabletospeak.③作原因状语Iwassurprisedtoseehimhere.Theywerepleasedtohearthegoodnews.Iamgladtomeetyou.④在形容词后作状语3/7Thisquestioniseasytoanswer.6)作补语Hewantshissontobecomealawyer.Sheencouragedmetotryagain.Theypersuadedhimtogiveupsmoking.Theybelievehimtobewritinganewbook.他们认为他正在写一本新书。Hewantedthelettertobetypedatonce.Theletterwaswantedtobetypedatonce.(主补)①感官动词feel,hear,see,watch,notice,observe③help：helpsb.do……或helpsb.todo……两种说法均可。Ioftenhearhimsingthissong.Thebossmadetheworkerswork12hoursaday.当此类句子改为被动语态时，要补上to.Heisoftenheardtosingthissong.Theworkersweremadetowork12hoursaday.☆在think,find,consider,discover等动词后常用tobe+adj.结构作宾补，有时tobe可Weallthink/consider/find/discoverhim(tobe)kindandhonest.我们都认为/发现他既2.不定式的时态/方式1)一般式：有时与谓语动词表示的动作同时发生，有时发生在谓语动词的动作之后。(todo)Heseemstoknowthis.Ihopetoseeyouagain.=IhopethatI'llseeyouagain.我希望再见到你。Heseemstobeeatingsomething.3)完成式：表示的动作发生在谓语动词表示的动作之前。(tohavedone)I'msorrytohavegivenyousomuchtrouble.Heseemstohavecaughtacold.进行式：(tohavebeendoing)Sheisknowntohavebeenworkingontheproblemformanyyears.Hepretendedtohavebeenstudying.3.动词不定式的否定式：nottodoTellhimnottoshutthewindow.ShepretendednottoseemewhenIpassedby.A.toshutnotB.nottoshutC.tonotshutD.notshut例2)Shepretended___mewhenIpassedby.A.nottoseeB.notseeingC.tonotseeD.havingnotseen例3)Mrs.Smithwarnedherdaughter___afterdrinking.A.nevertodriveB.toneverdriverC.neverdrivingD.neverdrive例4)Theboywantedtoridehisbicycleinthestreet，buthismothertoldhim____.A.nottoB.nottodoC.notdoitD.donotto4/75/7例5)Thepatientwaswarned___oilyfoodaftertheoperation.A.toeatnoB.eatingnotC.nottoeatD.noteating4.动词不定式的省略makeseewatchnoticeobservehearsmellfeelfind补时，省略to。help可带to，也可不带to→helpsb(to)dosth。2)Whynot后面接不带to的不定式。常用来表建议。Whynothaveabreak?3)but和except：but/except前的部分出现实义动词do时，其后面出现的动词不定式可以Hewantstobelieveanythingbuttotakethemedicine.LastnightIdidnothingbut(to)watchTV.Hedoeseverythingexcept(to)work.4)由and,or或than连接的两个不定式，第二个不定式的to可以省去。例如：HewantstomovetoFranceandmarrythegirl.5)通常在discover,imagine,suppose,think,understand等词后，可以省去tobe：Heissupposed(tobe)anhonestman.例1)----Iusuallygotherebytrain.----Whynot___byboatforachange?A.totrygoingB.tryingtogoC.totryandgoD.trygoing例2)Pauldoesn'thavetobemade___.Healwaysworkshard.A.learnB.tolearnC.learnedD.learning5不定式特殊句型soasto：表示目的；其否定式是soasnottodo。IoftenreadChinaDailysoastoimprovemyEnglish.Tomkeptquietabouttheaccidentsoasnottolosehisjob.汤姆对事故保持沉默是为了6/7Goinquietlysoasnottowakethebaby.轻点进去，别惊醒了婴儿。注：同样表示目的，inorderto可放在句首，但soasto不可放在句首。6不定式特殊句型too…toHeistooexcitedtospeak.I'mafraidtheboxistooheavyforyoutocarryit。2)如too前有否定词，则表达一种委婉含义，意为"不太"。It'snevertoolatetomend.改过不嫌晚。I'monlytoopleasedtobeabletohelpyou.我非常高兴能帮助你。Hewasbuttooeagertogohome.他非常想回家。7.常见后接动名词与不定式语义不同的有10组：(1)stoptodostopdoing(2)forgettodoforgetdoing(3)remembertodorememberdoing(4)regrettodo(当时或现在遗憾地做什么)regretdoing(做了某事而感到遗憾/后悔)(5)ceasetodoceasedoing(同stop)(6)trytodotrydoing(7)goontodogoondoingng(9)beinterestedtodo(对做某事感兴趣，想了解某事)beinterested(in)doing(对某种想法感兴趣，doing通常为想法等)(10)meantodo(打算，意欲)meandoing(意味着)例1.Wearenotinterested_________tostories,butnowwe’dbeinterested_________yourstory.7/7A.inlistening,inhearingB.tolisten,tohearC.inlistening,tohearD.tolisten,inhearingedininbeinterestedindoingsth=对做某事感兴趣(指一般性的动作)beinterestedtodosth=很有兴趣做某事，很想做某事(指尚未发生的动作)如：Heisinterestedinlisteningtostories.他对听故事很感兴趣。We’dbeinterestedtohearyourstory.