情态动词
情态动词情态动词具有一定得词义,没有人称和数的变化,不能单独构成谓语,和谓语动词连用表示委婉语气或表示愿望、态度或推测等意义。
一、情态动词的类型和特征情态动词的类型只作情态动词的有:must;can(could);may(might)只作情态动词也可作实义动词的有:need,dare可作情态动词也可作助动词的有:will(would);shall(should)具有情态动词的某些特征的有:haveto;oughtto;hadbetter
2.情态动词的特征(1).有一定的词义,但不能单独作谓语,必须和行为动词或系动词连用,构成谓语。(2)表示说话人的态度或语气,无人称和数的变化(haveto例外,其第三人称单数形式为hasto)Hehastowalkhome.⑶情态动词后面跟的动词须用原形。
二、情态动词的用法1.Can的用法⑴常用来表示能力,意为“能,会”。eg:Shecanswimfast,butIcan’t.⑵表示请求或许可,意为“可以”。eg:Canyougoshoppingwithus?⑶表示推测,意为“可能”,常用于否定句或者疑问句中,此时can’t意为不可能。eg:Canthenewsbetrue?Thatcan’tbeourteacher.HeisonavisittotheGreatWall.
----IthinkMissGaomustbeinthelibrary.Shesaidshewouldgothere.---No.She_____bethere.Ihavejustbeenthere.A.can’tB.mustn’tC.needn’tD.wouldn’t
4)can’t可用来作MayI….?的否定回答----MayIgosurfingalonethisafternoon?----No,youcan’t.It’sdangerous.5)can和beableto两者都是表示“能力”是用法相同,但can只有原形和过去式could两种形式,其他时态要用beableto来表示。另外,beableto常常有“成功做了某事”的意味Jimcan’tspeakEnglish.Wewereabletoreachthetopofthemaintainatnoon.
2.Could的用法⑴can的过去式,意为“能,会”,表示过去的能力。eg:Hecouldwritepoemswhenhewas10.⑵could在疑问句中,表示委婉的语气,此时could没有过去式的意思。eg:Couldyoupleasespeakalittlelouder?CouldIuseyourpen?Yes,youcan/No,youcan’t.
---CouldIcrossthestreethere?---Ofcourseyou______.couldB.canC.areabletoD.will
3.may的用法⑴may表示请求、许可,意为“可以”,比can要正式。eg:MayIaskyouaquestion?Youmaygohomenow.⑵表示推测,谈论可能性,意为“可能、也许”,一般用于肯定句。eg:Itmayraintomorrow.Shemaybeathome.⑶may的过去式为might,表示推测,可能性低于may。eg:Heisawayfromhome.Hemightbesick.(4)may表示祝福Mayyoubehappy!
(5)can和may1)Can和may均可用来征求意见或许可,意为“可以”,一般可互换使用Can/MayIhelpyou?2)may和can表示可能性时的区别:①在肯定句中用may,might,不用can;②在疑问句中表示推测用can;③在否定句句中用can’t(不可能)Shemaybeintheclassroom.Wherecantheybenow?Thatcan’tbetrue.
(6)maybe和maybe用法区别常用位置maybemay为情态动词,be动词原形句中,做谓语maybe副词,大概、也许,相当于perhaps句首,作状语Hemaybewrong,butI’mnotsure.
----Haveyoudecidedwhichseniorhighschooltochoose?----Notyet.I____gotoMoonlightSchool.A.mustB.mayC.needD.should----Whatwilltheweatherbeliketomorrow?----It____berainy,cloudyorsunny.Whoknows?mustB.mightC.shallD.should
情态动词练习1讲解1.----_____Ihavealookatyournewwatch?----Yes,please.MayB.NeedC.DareD.Must2.Tomisyoungbuthe_____flyakitebyhimself.mayB.canC.needD.must
3.Theworkistoohardforhim.He_____finishitontime.can’tB.mustn’tC.shouldn’tD.needn’t4.Thebookstorewasopen,soI____buythebook.canB.can’tC.didcanD.wasableto
5.LastyearI____drive.Iusedtakethebus.couldB.couldn’tC.shouldD.shouldn’t6.----Couldwesmokehere?----I’mafraidyou____.couldn’tB.can’tC.areabletoD.will
7.----Ihearyou’vegotanewiPhone4S.____Ihavealook?----Yes,certainly.MayB.DoC.ShallD.Should8.----Where’sLucy?----I’mnotsure.She_____intheschoollibrary.maybeB.mustbeC.maybeD.willbe
9.----WhereisTom?----_____heisathome.Hedidn’tfeelwellyesterday.MaybeB.MaybeC.May10.----______Iswimhere?----I’msorry.Children____swimalonehereMust;can’tB.May;mustCan;mustn’tD.Can’t;can
4.Must的用法⑴must表示“一定要,必须”。否定形式是mustn’t,表示“禁止,不许可”。eg:YoumuststayhereuntilIcameback.Youmustn’tparkyourcarinfrontoftheentrance.⑵对must引导的疑问句,肯定回答为must,否定回答为needn’t或者don’thaveto。eg:----MustIfinishmyhomeworknow?----No,youneedn’t.
⑶must常常指有根据的,比较有把握的推测,意为“一定是,准是”,这种用法只能用于肯定句当中。eg:Thelightison.Hemustbeathomenow.当must表示肯定判断、推测的时候,其反意疑问句要用实际问句的助动词来构成。eg:Shemusthavefinishwriting,hasn’tshe?
⑷must和haveto①must侧重于个人意志和主观上的必要,意为“必须,应该”。eg:IknowImuststudyhard.②haveto侧重于客观上的必要,意为“不得不”。它有一般现在时第三人称单数形式hasto和过去形式hadto。eg:Mybrotherwasveryill,soIhadtocallthedoctoratmidnight.③haveto的否定形式是don’thaveto,相当于needn’t,意为“不必”;mustn’t表示“禁止,不允许”.
(5)can’t和mustn’t表否定推测时应用can’t,mustn’t意为“禁止,不允许”,不用来表推测,在肯定句中用must表推测,意为“一定”
----Mom,mustIcleanmyroomnow?----No,you____.Youcandoittomorrow.can’tB.needn’tC.mustn’tD.shouldn’t
5.need的用法⑴need表示“需要,必须”,主要用于否定句和疑问句当中,否定形式为needn’t,意为“没有必要,不必”。用need提问时,肯定回答是must,否定回答为needn’t.eg:---NeedIstayhereanylonger?⑵need可作实义动词,此时还有人称,数和时态的变化,后面多接动词不定时。eg:Ineedtodoitrightnow.Heneedstolearnmoreaboutthegirl.
注意:对need的词性判断常为难点,need后加todo说明need为实义动词,用助动词提问或否定;need后加doing表示被动意义;若need后加do的动词原形,则need为情态动词Youneedn’tseehim,butImust.Youdon’tneedtocomeifyoufeelsick.
(6).dare表示“敢于”,用作情态动词时,无人称变化,只用于否定句、疑问句和条件句Marydarenottouchthesnake.用于实义动词时,要注意人称和时态的变化,后面跟不定式Ihaveneverdaredtotellhimaboutit.注意:dare作实义动词时,其疑问句或否定句后面的不定式符号常省略。Hedidn’tdare(to)disobey.
You____swiminthispartofthelake.It’sdangerous.mustn’tB.needn’tC.won’tD.maynotIenjoythepartyverymuch,butI____gohome.It’stoolate.A.havetoB.mayC.mustn’tD.should’t
6.shall,should,will,would的用法⑴shall常用于疑问句当中,表示征求对方的意见(多用于第一、三人称),用在第一人称或第三人称的疑问句中eg:shallwegooutforawalk?Shallhecomeatonce?一般回答:Yes,please./Allright./No,thankyou.⑵Shall用于第二、第三人称,表示说话人给对方命令、警告、允诺或威胁。eg:Youshallfailifyoudon'tworkharder.(警告)HeshallhavethebookwhenIfinishreading.(允诺)Heshallbepunished.(威胁)
⑶should意为“应该”。可表示劝告、建议、义务、责任等。eg:Weshouldprotecttheenvironment.
⑷will表示主语的决心或意愿;也可表请求或询问,用于第二人称。eg:Iwillneverdothatagain.IwillhelpyouifI’mfreethisafternoon.Willyoupassmethebook?⑸will表示习惯、请求,固有性质等。eg:Everydayhewillsitherehourafterhourdoingnothing.(习惯)WillyouhelpmewithmyEnglish?(请求)
7.hadbetter的用法hadbetter意味“最好”,没有人称的变化,后接不带to的不定式,其否定形式为hadbetternot.eg:Wehadbettergonow.Youhadbetternotgivethebooktohim.
----Howwastheyouthclublastnight,Mark?----Itwasgreatfun.You______havecome.MustB.canC.shouldD.mayYoulooktirednow.You_______stayathomeandhavearest.hadtoB.hadbetterC.wouldliketoD.wouldrather
PS:在英语中,我们可以用其他多种方式提出我们的建议或征求对方意见。(1).用“Let'sdo...”来提出建议。e.g.Let'sgoforawalkaftersupper.(2).用“What/Howabout...?”来提出建议;about后接名词或动词ing形式。e.g.Whatabout/Howaboutadrink?Whatabout/HowabouttakingTomwithus?
(3).用“Whynot...?”来提出建议,表示“何不……”not面后接动词原形。“Whynot...?”实际上是“Whydon'tyou/we...?”的简略形式。e.g.Whynotmeetattheschoolgateateight?Whydon'twestayhereanotherday?(4).用“Wouldyoulike...?”来提出建议,意思是“你想要……吗?”Wouldyoulike后可接名词或不定式。如:Wouldyoulikeacupoftea?Yes,please.No,thankyou.Wouldyouliketogoandseeher?Yes,I’dliketo.No,thankyou
“去游泳好吗?”Shallwegoforaswim?Let'sgoforaswim,shallwe?Whatabout/Howaboutgoingswimming?Whynotgoforaswim?Wouldyouliketogoforaswim?
willwill在therebe句型中的形式及其句式变换。将有由于“一般将来时”的结构可以用“will+动词原形”来表示,所以therebe句型的一般将来时的形式就是therewillbe。(一定不能说therewillhave)Therearemanystudentsinourschool.→Therewillbemanystudentsinourschool.
含有情态动词的疑问句的回答对may引出的问句,可以有下列回答方式:Yes,youmay.Yes,ofcourse.Yes,certainly.Sure.No,youmustn’t.No,youcan’t.2.对must引出的疑问句,回答方式为:Yes,…must.No,…needn’t/don’thaveto.
3.could在疑问句中,表示委婉的语气,此时could没有过去式的意思。e.g.—CouldIuseyourpen?----Yes,youcan./No,youcan’t.4.shall引出的疑问句用于第一人称或第三人称中,表示征求对方意见或客气的请求。其回答方式有以下几种:Yes,please.Allright.No,thankyou.
5.wouldyou…的回答方式有以下几种:Yes,Iwill.(No,Iwon’t.)Sure.(I’msorry,Ican’t.)Allright/OK/Withpleasure.Certainly.(No,thankyou.)Yes,please.Wouldyouliketogoshoppingwithme?Yes,I’dliketo./No,thanks(thankyou).Wouldyoulikesomewater?Yes,please./No,thanks(thankyou)—WouldyoudomeafavourandpassonmythankstoLily?—________.A.That’srightB.WithpleasureC.Itdoesn’tmatterD.Notrouble