情態(tài)動(dòng)詞can may must need及練習(xí)

情態(tài)動(dòng)詞can的用法，表示某人能做某事。肯定句：主語(yǔ)+can+動(dòng)詞原形+其他Icanplaythepiano.否定句：主語(yǔ)+can+not(can’t)+動(dòng)詞原形+其他Icannot(can’t)playthepiano.一般疑問(wèn)句：Can+主語(yǔ)+動(dòng)詞原形+其他?Canyouplaythepiano?特殊疑問(wèn)句：特殊疑問(wèn)詞+can+主語(yǔ)+動(dòng)詞原形+其他?Whatcanyouplay?Whocanplaythepiano?情態(tài)動(dòng)詞must,can,could,may,might表推測(cè)的用法：情態(tài)動(dòng)詞中的must,can,could,may,might都表推測(cè)。其中must的可能性最大，can/could次之，may/might最小。具體用法如下：1.must的用法（1）表示推測(cè)“可能性”時(shí)，意思是“一定、準(zhǔn)是”，語(yǔ)氣較肯定，較有把握。HemustbeAmerican.=ItiscertainthatheisAmerican.他準(zhǔn)是個(gè)美國(guó)人。（2）must表推測(cè)只能用于肯定句。如果要表示“一定不、肯定不”的意思時(shí)，應(yīng)用can`t,如詢問(wèn)某種可能時(shí)，應(yīng)用can。Hemustknowmyaddress.他肯定知道我的地址。（一定）Hecan`tknowmyaddress.他肯定不知道我的地址。（一定不）Canheknowmyaddress?他知道我的地址嗎？（詢問(wèn)可能性）（3）must表示推測(cè)時(shí)，可以推測(cè)現(xiàn)在/正在發(fā)生的動(dòng)作/過(guò)去發(fā)生的動(dòng)作。Hemusthaveacarnow.（現(xiàn)在）他一定有輛小汽車。Hemustbedoinghisexercisesintheclassroom.（正在進(jìn)行）他一定在教室里做練習(xí)。Hemusthavefinishedthework.（過(guò)去發(fā)生）他一定已完成了工作。注：must表示推測(cè)時(shí)很少用于將來(lái)的情況。一般不用Hemustcometomorrow.可用It`scertain/I`msurethathewillcometomorrow.（4）在反意疑問(wèn)句中，當(dāng)附屬部分含有表示推測(cè)意義的must時(shí)，疑問(wèn)部分的助動(dòng)詞應(yīng)與must后面的動(dòng)詞在非推測(cè)情況下的用法保持一致。Hemustbeaworker,isn`the?（現(xiàn)在）他準(zhǔn)時(shí)個(gè)工人，是嗎？Itmusthaverainedlastnight,didn`tit?（過(guò)去）昨晚一定下雨了，是不是？YoumusthavelearnedEnglishformanyyears,haven`tyou?（完成時(shí)）你一定學(xué)了好多年英語(yǔ)，是嗎？2.can/could的用法（1）can表示推測(cè)“可能性”時(shí)，往往用于否定句或疑問(wèn)句。Can`t“一定不”，語(yǔ)氣很肯定。can在疑問(wèn)句中意思是“會(huì)、可能”。Hecan`tbeathome.=Itisimpossiblethatheisathome.他一定不在家。（2）can/can`t后可接進(jìn)行時(shí)/完成時(shí)，表示對(duì)現(xiàn)在發(fā)生的動(dòng)作或過(guò)去發(fā)生的動(dòng)作進(jìn)行推測(cè)。Theycan`tbereadinginthelibrary.他們一定不在圖書館讀書。Hecan`thavegonetoShanghaiforIsawhimaminuteago.他不可能去了上海，我剛才還看見他。It`ssolate.Wherecanshehavegone?天晚了，她可能去哪兒了呢？（3）在反意疑問(wèn)句中，當(dāng)陳述部分含有表示推測(cè)意義的can`t時(shí)，疑問(wèn)部分的助動(dòng)詞應(yīng)與can`t后面的動(dòng)詞在非推測(cè)情況下的用法保持一致.Hecan`tbeateacher,ishe?他不是教師，是嗎？Shecan`thavefinishedherhomework,hasshe?她一定沒有完成家庭作業(yè)，是不是？（4）could可用于表示某事有可能發(fā)生或可能是事實(shí)。Don`teatit.Itcouldbepoisonous.不要吃它，可能有毒。Theplanecouldbedelayedbyfog.飛機(jī)可能會(huì)因?yàn)殪F晚點(diǎn)。（5）could還可以用于表示客氣、委婉、禮貌的請(qǐng)求語(yǔ)氣。Excuseme,couldyoutellmethewaytothebusstation?Couldyouhelpme?（6）couldn`t表示否定推測(cè)，表示某事不可能真實(shí)，或由于特定事實(shí)或環(huán)境某事肯定不會(huì)發(fā)生。Itcouldn`tpossiblybepoison.這不可能是毒藥。注：有時(shí)與形容詞的比較級(jí)連用強(qiáng)調(diào)某人或某物不可能再更多地具有某種屬性。Youcouldn`tbemorewrong.你真是大錯(cuò)特錯(cuò)。Icouldn`tbehappier.我簡(jiǎn)直是幸福極了。3.may和might的用法（1）may,might表示推測(cè)“可能性”時(shí)，意思是“可能”、“也許”，語(yǔ)氣沒有must肯定。Hemay/mightbeAmerican.=ItispossiblethatheisAmerican.他可能是個(gè)美國(guó)人。注：might不表示過(guò)去時(shí)態(tài)，只是語(yǔ)氣上比may更委婉，表示的可能性更小。（2）may,might表推測(cè)時(shí)，可以用于否定句，意思是“可能不、也許不”，但不用于疑問(wèn)句。Hemay/mightnotbeathome.他也許不在家。（3）may,might可以推測(cè)現(xiàn)在正在發(fā)生的動(dòng)作或過(guò)去發(fā)生的動(dòng)作。Hemay/mightbesleepingnow.現(xiàn)在）他可能正在睡覺。Theboymay/mightnotbewatchingTVathome.（現(xiàn)在）這個(gè)男孩可能沒在家看電視Thesestudentsmay/mighthaveseenthefilmbefore.（過(guò)去）這些學(xué)生以前可能看過(guò)這部電影。（4）may,might還可以推測(cè)將來(lái)的情況。Ithinkweshouldtakeraincoatwithus,itmayrain.我想我們應(yīng)該帶上雨衣，可能要下雨了。Shemightnotcomethisafternoon.她今天下午可能不來(lái)了。Exercise:Completethesentencesusing“must”or“can`t”.1.Ihavetriedtocallhimattheoffice,butthereisnoreply.He_____beathome.2.Theyhaveboughtanewcar.They_____havealotofmoney.3.SheiscarryingaJapanesenewspaper.She____beChinese.4.Hegoesabroadalot.He______haveanimportantjob.5.Sheisaprofessorattheuniversity.She_____beveryclever.6.SheisactinginaShakespeareplaytomorrow.She_____beanactress.【隨堂練習(xí)】一.選擇填空1.Ithoughtyou______likesomethingtoread.SoIhavebroughtyousomebook.A.oughtB.mightC.couldD.must2.–ThatmanmustbeSarah`shusband.--No,he______beherhusband.Sheisstillsingle.A.can`tB.mustn`tC.maynotD.oughtto3.Peter______comewithustonight,butheisn`tverysure.A.mustB.mayC.canD.will4.–What______itbe?--It______beamailbox,foritismoving.It______beacar.A.can;can`t;mustB.can;can;mustC.can;mustn`t;mustD.must;mustn`t;can5.–Look,someoneiscoming.Guess______.--Jack.He`salwaysontime.A.whocanitbeB.whohemayC.whohecanbeD.whoitcanbe6.–IsawMaryinthelibraryyesterday.--You______her.Sheisstillabroad.A.mustn`tseeB.can`thaveseenC.mustn`thaveseenD.couldn`tsee7.David,you_____playwiththevaluablebottle,you_____breakit.A.won`t;can`tB.mustn`t;mayC.shouldn`t;mustD.can`t;shouldn`t8.SusanrefusestomarryJacknow.She_____hermind.A.mustchangeB.shouldhavechangedC.musthavechangedD.wouldhavechanged9.Sue______cometogetherwithustonight,butsheisn`tverysureyet.A.mustB.mayC.needD.will10.AuntMargaret_____therain,otherwiseshewouldhavearrivedherebynow.A.musthavemissedB.shouldhavemissedC.hadmissedD.mightmiss1．Whoisthemanoverthere?IsitMr.Wu?—It________him,butIamnotquitesure.A.maybeB.maybeC.isD.mustbe2．Somepeoplefeelsickwhentheyreadabookinacaroronaboat．A．mustB．shouldC．mayD．need3．---MustIgotomedicalschoolandbedoctorlikeyou，Dad？---No,you__________,son.You’refreetomakeyourowndecision.A.can’tB.mustn’tC.shouldn’tD.don’thaveto4．Youbehungryafterthelongwalk.Helpyourselftosomecakes.A.shouldB.mustC.needtoD.oughtto5．Couldyouplease_____thepianosoloudly?Yourbrotherishavingarestnow.A.nottoplayB.notplayC.don’tplayD.tonotplay6．—ThatpinkT-shirtwithPingAn’spictureonit______belongtoMissMa.Sheadmireshimalot.—No,it_____behers.Shehatespinkcolour.A.must,can’tB.may,can’tC.can,mustn’tD.must,mustn’t7．---MustIansweritinEnglish?---No,you_______.YoucanuseChinese.A.shouldn’tB.can’tC.mustn’tD.needn’t8．----________wegoswimminginXishuanghuLaketoday?----Oh,no.It’s________coldtoswimonsuchdays.Iwillcatchacold.A.Will;veryB.Will;tooC.Shall;veryD.Shall;too9．Peoplewhodrinkwine____________todriveafterMayDay.’tallow’tallowed’tallowD.mustn’tbeallowed10．—Iwasaskedtoattendthemeetingbeforeeight.—Oh,you________.I'msorryfornottellingyouthatwehavechangedtheplan.A.mustB.can'tC.mayD.needn't11．Youhaveworkedforalongtime.You____________beverytired.A.mustB.can’tC.could