高中英語語法情態(tài)動詞講解精致版講解隨手練

學(xué)習(xí)好資料歡迎下載學(xué)習(xí)好資料歡迎下載學(xué)習(xí)好資料歡迎下載情態(tài)動詞一、情態(tài)動詞用法**情態(tài)動詞具有詞匯意義，但意義不夠完整，一般不能單獨作謂語。情態(tài)動詞表示說話人的語氣和態(tài)度。can;could;may;might;shall;should;will;would;must;dare;need;oughtto**主要歸納為以下幾個考查熱點：1.情態(tài)動詞基本用法；2.情態(tài)動詞表示推測和特定的語氣；3.情態(tài)動詞+havedone結(jié)構(gòu)；4.情態(tài)動詞和各種時態(tài)連用的含義；Hemaybeateacher.Hemaybereadingintheclassroom.Hemayhavefinishedherhomework.Itmusthavebeenrainingheavilywhenhegotback,forhewaswetover.1.can的用法①表示現(xiàn)在的能力（相當(dāng)于beableto）He______/_____________readFrenchfluentlynow.注：1)can的主語是人或物,beableto的主語是人e.g.She_________singthesonginEnglish.Thismachine____makeyoufeelcomfortable.2)表示特定的某一過去能力或表示成功地做了某事時，只能用was/were

able

to，

不能用could。He

_____escapefrom

Europe

before

the

war

broke

out.②表示對現(xiàn)在的推測（只用于否定句和疑問句中，肯定句中用may/might）A:Look,someoneiscoming.Who______itbe?B:It_____betheheadmaster.A:It_______behim.HehasgonetoBeijingonbusiness.B:Thenit_______beMr.Zhang.Helooksliketheheadmaster.③用于肯定句中表示【客觀上或理論上】的可能性，“有時候可能會”（不是推測）Childrencanbeannoyingsometimes.Accidentscanhappenonsuchrainydays.④用在否定句、疑問句、感嘆句中常表驚訝、懷疑、不相信的語氣。Howcanyoubesocareless?Whatcanhepossiblymean?⑤表示請求和允許----CanIgonow?----Yes,youcan./No,youcan’t.【在推測可能性方面的must＞may＞might＞can’t】參考答案為：①can/isableto;1)can/beableto;can;2)was

able

to

②can;must;can’t;maycould的用法①表示過去的能力，可用________________________替換。（注意后者還有另一個意思）He_________/________________rideabikewhenhewasonly7.②表示委婉的請求(注意回答用詞)----CouldIuseyourcomputer?----Certainly,youcan.參考答案為：①was/wereableto;②could;wasableto3.may/might的用法**may①表示請求或許可;MayIaskyouaquestion?②表推測（可能性?。怀Ｓ糜诳隙ň浠蚍穸ň渲?，不用于疑問句中）Hemaybealawyer.Hemaynotbealawyer.**might①表委婉的請求;----MightIaskyouaquestion?----Surely,youmay.----May/MightIsmokeinthisroom?----Yes,youcan.(No,youcan’t/mustn’t.)②表推測（可能性比may還?。〩emightbealawyer.**may用于祈使句,表示祝愿.MayyouryearsatColumbiabethehappiestofyourlife,andmayyoublossomintojustwhatyoudreamtobe.希望在哥倫比亞大學(xué)學(xué)習(xí)的四年成為你一生中最快樂的時光！祝愿你夢想成真！Maythehopeandinspirationwereceivefromyoubegivenback.Mayyoureturnsafeandsound.Mayyoubehappy! 4.must的用法①“必須”_________表示禁止，“千萬不可以；不準(zhǔn)”在表“必須”這個意思之下，須要注意對于must一般疑問句的回答---Mustwecleantheclassroomnow?---Yes,you________./No,you_______/________________.②表示推測，“肯定，一定”，只用于肯定的陳述句中Hemustbealawyer.他一定是個律師；他現(xiàn)在不可能在家，因為昨天他去了美國。判斷：Hemustn’tbeathome,becausehewenttoAmericayesterday.()在表“必定，一定”這個意思之下，尤其需要注意must有關(guān)的反意疑問句1)Youmustbejoking,__________?2)Hemustbealawyer,__________?3)Hemustbedoinghishomeworkupstairsnow,__________?4）Hemusthavearrivedalready,__________?5）Hemusthavearrivedyesterday,_________?6）Hemusthavefinishedtheworkbytheendoflastmonth,_________?7）Itmusthaverainedlastnight,_________?③“非要，偏要，一定要”----Whoisthegirlstandingthere?----Well,ifyou______know,hernameisMabel.參考答案：①mustn’t;must;needn’t/don’thaveto；②判斷：錯誤的寫法：其中mustn’t要改為can’t；反義疑問句：1）aren’tyou;2）isn’the;3）isn’the;4）hasn’the(若句中不含任何時間狀語，即可用對應(yīng)的現(xiàn)在完成時完成反意疑問句);5）didn’the(若句中含有過去的時間狀語，用一般過去時完成反意疑問句);6）hadn’the(若句中含有過去完成時的時間狀語，用過去完成時完成反意疑問句);7）didn’tit③must;5.shall的用法①用于【第一、三人稱】的疑問句中表示說話人征求對方的意見或向?qū)Ψ秸埵?；ShallIhelpyoucarrythatbox?_______hewaitoutsideorcomein?②用于【第二、三人稱】的陳述句中表示說話人給對方的承諾、警告、威脅、強制、命令等語氣。Ifyouworkwell,youshallhavehigherpay.（承諾）Ifyouwon’tdoasItellyou,youshallnotgototheparty.（威脅）Peopleunder18shallnotbeemployedinnightwork.（強制）Ifyoudon’tgetout,Ishallknockyoudown.（警告/威脅）③Let’sgotogether,____________?Letusgotogether,______________?參考答案：①Shall;③shallwe;willyou.6.should的用法①表示義務(wù)，“應(yīng)該，應(yīng)當(dāng)”，用于各種人稱Youshouldbepolitetoyourteacher.Youshouldn’tspendsomuchtimeplayingcomputergames.②根據(jù)以往的經(jīng)驗或事實做出合理的推斷，“照說應(yīng)該,想必，估計”Iftheystarttoday,theyshouldarrivethereintwodays.Itis12o’clock,andIshouldbehomeintenminutes.IwonderwhereMaryis.Sheshouldbeherenow.**Should用于if引導(dǎo)的條件狀語從句中表示某件事情的可能性很小，意思是“萬一”。---WhatcanIdoforyou?---IfyoushouldseeMr.Smith,givehimmyregards.③在某些從句中(如與“建議”、“要求”、“命令”相關(guān)的名詞性從句)，表示虛擬語氣．Itissuggestedthatwe(should)makebetteruseoftheschoollibrary.Itishightimethatwe_______/___________theproblem.④表驚訝、遺憾的語氣，“竟然”Itisapitythatsheshouldhavelostallhismoney.Itissurprisingthatheshouldbesofoolish.參考答案：③solved/shouldsolve(固定句式Itishightimethatsb過去時/should+動詞原形；是某人做某事的時候了。Should不可以省略。)7.will的用法①表示目前的表示某種傾向或習(xí)慣性動作。Hewillsitthereforhours,reading.EverySaturdayeveningtheywillplaychesstogether.Boyswillbeboys.②表示意志，意愿IhavemadeupmymindtogoandIwill.Iwilldomybesttohelpyou.注意下面這句話：If

you

will

read

the

book,

I′ll

lend

it

to

you.

如果你愿意讀這本書，我會把它借給你。8.would的用法①表示過去的習(xí)慣性動作（不表狀態(tài)）OnSundayshewouldcometoseehisagingparents.Heusedtobeaquietboy.()Hewouldbeaquietboy.()②委婉的請求----___________youdomeafavor?----Ofcourse,I_________.Wouldyoupleasetellmehowtogettothezoo?③表意愿（will的過去式）Itoldhimnottogobuthewouldn’tlistentome.④用于虛擬語氣中Ifhewereintown,hewouldhelpyou.(______________________________)Ifyouhadcomeearlier,youwouldhaveseenhim.(______________________________)參考答案：①√;×②Would;will;④對現(xiàn)在的虛擬；對過去的虛擬9.dare的用法①情態(tài)動詞一般用于否定句、疑問句、條件狀語從句中，后接動詞原形，一般現(xiàn)在時中，謂語動詞無三單。過去式為dared。She

_______

out

alone

at

night.

她晚上不敢一個人出去。Not

one

of

them

________

mention

this.

他們誰也不敢提這件事。

Thatwaswhyhe______doso.那就是他為什么敢這樣做的原因。②實義動詞daretodo;don’t/doesn’t/didn’tdaretodo過去式為dared。Jack______theriver.Helookedafraid.A.darenottocrossB.darednotcrossC.darednottocrossD.doesn’tdaretocross參考答案：①darenotgo;dared;dared;②B10.need的用法①情態(tài)動詞。僅用于否定句和疑問句中，肯定句中一般用must,oughtto,should代替；詞形只有一個，沒有將來時、過去時或第三人稱單數(shù)形式，后面接動詞原形。②實義動詞。needtodo；don’t/doesn’t/didn’tneedtodo過去式為needed。----_________Ifinishtheworktoday?----Yes,you__________./No,you____________.“need”作為實義動詞時，通常用法是：sb＋need＋todosth＋need＋doing=sth＋need＋tobedone請看下面的例子：1．WeneedtocollecttheparcelbeforeweleaveforEngland．去英國之前，我們需要收拾好行李。2．Weneedtotellhimthetruth．我們需要告訴他真相。3．Mycarneedsrepairing．我的汽車需要修理。4．Theflowersneedwatering．這些花需要澆水。5．Hisleathershoesneedstobemended．他的皮鞋需要修補。6．Herroomneedscleaning．她的房間需要打掃。參考答案：②Need；must；needn’t/don’thaveto11.“情態(tài)動詞+havedone”結(jié)構(gòu)含義①_________________過去一定做過某事②_________________過去可能做過某事③________________過去不可能做過某事④_________________過去本應(yīng)該做某事卻未做⑤_________________過去本不應(yīng)該做某事卻做了⑥_________________過去本不必做某事卻做了⑦_________________過去有能力/條件做某事卻未做參考答案：①musthavedonesth;Itmusthaverainedlastnight,forthegroundiswet.②may+have+done用于肯定句中?！猈hathashappenedtoGeorge?—Idon'tknow.Hemayhavegotlost.③can’thavedonesth.Mr.Smithcan'thavegonetoBeijing,forIsawhiminthelibraryjustnow.④should/oughttohavedonesth.Tom,youaretoolazy.Theworkshouldhavebeenfinishedyesterday.IoughttohavegonehomelastSunday.我理應(yīng)上星期日回家.⑤shouldn’t/oughtnottohavedonesth.Look,Tomiscrying.Ishouldn'thavebeensoharshonhim.Yououghtnottohavegivenhimmorehelp.你不應(yīng)該幫助他那么多.⑥needn’thavedonesth.Ineedn'thaveboughtsomuchwine—onlyfivepeoplecame.我本來沒有必要買這么多酒，只來了五個人。⑦could(不用can)+havedone.Hecouldhavepassedtheexam,buthewastoocareless.二、鞏固練習(xí)()1.----HasJohnarrivedyet?----No,she__________anhourago.A.oughttocomeB.musthavecomeC.shouldcomeD.oughttohavecome()2.----I’msorry,I________atyoutheotherday.----Forgetit.Iwasabitoutofcontrolmyself.A.shouldn’tshoutB.shouldn’thaveshoutedC.mustn’tshoutD.mustn’thaveshouted()3.You_____notgetmysupportifyoudosuchathing.A.shallB.must C.should D.dare()4.Hearingthestepsofthepolice,thethief_______moveatall.A.daresnotB.darednottoC.didn’tdaretoD.notdare()5.Tom,you____leaveallyourclothesonthefloorlikethis!A.wouldn’tB.mustn’tC.needn’tD.maynot()6.----Ihearyou'vegotasetofvaluableAustraliancoins.___Ihavealook?----Yes,certainly.A.DoB.MayC.WillD.Should()7.––Shelooksveryhappy.She_____havepassedtheexam.––Iguessso.It’snotdifficultafterall.A.shouldB.couldC.mustD.might()8.ItisusuallywarminmyhometowninMarch,butit________berathercoldsometime.A.mustB.canC.shouldD.would()9.MyMP4isn’tinmybag.Where_____Ihaveputit?A.canB.mustC.shouldD.would()10.John,lookatthetime.________youplaythepianoatsuchalatehour?A.MustB.CanC.MayD.Need()11.----I'vetakensomeoneelse'sgreensweaterbymistake.----It__________Harry's.Healwayswearsgreen.A.hastobeB.willbeC.mustn'tbeD.couldbe()12.----Didyoulistentothespeech?----No,we________it.Butwehadalotoftrafficonourway..A.musthaveattendB.shouldn’thaveattendedC.couldattendD.couldhaveattended()13.----________wefinishalltheexercisesinclass?----Yes,you__________.A.Shall;willB.Need;canC.Can;mightD.Must;must()14.----What’sthename?----Khulaifi.________Ispellthatforyou?A.ShallB.WouldC.CanD.Might()15.Don'tbeworried.Thenews__________betrue.A.maynotB.mustn'tC.needn'tD.shan't()16.Somewarm-bloodedanimals__________hibernate.A.neednotB.doesnotneedtoC.needn'ttoD.donotneed()17.Hedidn'tagreewithmeatfirstbutI___________persuadehim.A.wasabletoB.wasableC.couldD.couldbeableto()18.I________havebeenmorethansixyearsoldwhentheaccidenthappened.A.shouldn’tB.couldn’tC.mustn’tD.needn’t()19.Allthedoctorsinthehospitalinsistedthathe______badlyillandthathe______atonce.A.shouldbe;shouldbeoperatedonB.shouldbe;wasoperatedonC.was;shouldbeoperatedonD.was;wasoperatedon()20.Weareallforyoursuggestionthatthediscussion______.A.beputoffB.wasputoffC.shouldputoffD.istobeputoff()21.Nooneanswersthephonecall.They______.A.musthavegoneoutB.can’thavegoneoutC.shouldhavegoneoutD.needn’thavegoneout()22.----Idon’tmindtellingyouwhatIknow.----You______.I’mnotaskingyouforit.A.mustn’tB.maynotC.can’tD.needn’t()23.----Mum,IclimbedtogettheTeddyBearfromthetopoftheshelf.----Mygoodness!You______yourself.You______dothatnexttime.A.musthavehurt;can’tB.shouldhavehurt;mustn’tC.couldhavehurt;mustn’tD.can’thavehurt;needn’t()24.Hedidnotagreewithmeatfirst,butintheendI______persuadehim.A.wouldB.couldC.mightD.wasableto()25.----Mustwehandinourhomeworkbeforeweleave?----No,you______.A.mustn’tB.needn’tC.havetoD.can’t()26.Canyouimaginethatasmartmanlikehim______makesuchastupidmistake?A.mightB.shouldC.wouldD.need()27.WhenthepoetwasstudyingatCambridgeUniversity,he______takeawalkalongthefamousrivereverymorning.A.willB.couldC.shallD.would()28.----MayIsmokehere?----Ifyou______,chooseaseatinthesmokingsection.A.shouldB.couldC.mustD.may()29.You______getanewbikeifyoudoverywellinthecomingexam.A.shallB.willC.shouldD.must()30.Hedidnotregretsayingwhathedidbutfeltthathe______itdifferently.A.couldexpressB.wouldexpressC.couldhaveexpressedD.musthaveexpressed情態(tài)動詞專項練習(xí)1.——Don’tforgettobringmynewbookstomorrowafternoon.

——No,I＿＿＿＿＿＿＿.

A.don’tB.can’tC.won’tD.couldn’t

2.Ihearyou’vegotasetofAustraliancoins.＿＿＿Ihavealook?

——Yes,certainly.

A.DoB.MayC.ShallD.Should

3.Heseldomlistenstoothers.He＿＿＿＿＿answerforwhathehasdone.

A.shallB.willC.canD.would

4.——MayIleavetheofficebefore5o’clockintheafternoon?

——No,I’mafraidyou＿＿＿＿＿＿＿.

A.needn’tB.shouldn’tC.mustn'tD.won’t

5.——ShallItellJohnaboutit?

——No,you＿＿.Idon’tknowhistelephonenumber.

A.needn’tB.wouldn’tC.mustn’tD.shouldn’t

6.MrBushisontimeforeverything.How＿＿＿itbethathewaslatefortheopeningceremony?

A.canB.shouldC.mayD.must

7.Thetrafficlightisred,soI＿＿＿stopmycar.

A.mustB.havetoC.canD.mustn’t

8.——Whathappenedtotheyoungtreesweplanted?

——Thetrees＿＿＿well,butIdidn’twaterthem.

A.mightgrowB.needn’thavegrown

C.wouldgrowD.wouldhavegrown

9.Iwasreallyanxiousaboutyou.You＿＿＿homewithoutaword.

A.mustn’tleaveB.shouldn’thaveleft

C.couldn’thaveleftD.needn’tleave

10.Children＿＿＿＿＿＿＿＿inpublicveryoften.

A.shouldbepraisedB.shouldn’thavepraised

C.shouldn’thavebeenpraised

D.shouldn’tbepraised

11.Let’scleantheclassroom,＿＿＿＿＿＿＿?

A.won’tyouB.shallweC.doweD.willnotyou

12.Tom＿＿＿＿＿＿＿showhisexamresultstohisparents.

A.darenotB.daredC.daretoD.daresnotto

13.Idon’tthinkhe＿＿＿＿＿＿＿anewbike.

A.needtobuyB.needsbuyC.needD.needbuy

14.——Nacy＿＿＿＿theletterfromhermother.

—No,shecan’thave.Thepostmanhasn’tcomeyet.

A.canreceiveB.canhavereceived

C.musthavereceivedD.mustreceive

15.She＿＿thefilm.Sheknowsnothingaboutit.

A.can’tseeB.can’thaveseen

C.mustseeD.mustn’thaveseen

16.Theymusthavebeenherethedaybeforeyesterday,＿＿＿＿?

A.mustn’ttheyB.didn’tthey

C.mustn’thavetheyD.hadthey

17.——Ididn’tseeheryesterday.

——Oh,butyou＿＿＿＿＿＿＿＿＿＿＿.

A.musthaveB.oughtto

C.shouldhaveD.cannothave

18.——MustItakeabus?

——No,you＿＿＿＿.Youcanwalkfromhere.

A.mustnotB.don’t

C.don’thavetoD.hadbetternotto

19.—Whydoyoumakemedoso?

—Iamsorrythatyou＿＿＿＿＿dosuchathing.

A.wouldB.canC.shouldD.may

20.—Willyoustayforlunch?

—Sorry,＿＿＿.Mybrotheriscomingtoseeme.

A.Imustn’tB.Ican’tC.Ineedn’tD.won’t

21.Whatwouldhavehappened＿＿＿＿,asfarastheriverbank?

A.ifBobhaswalkedfartherB.ifBobshouldwalkfarther

C.hadBobwalkedfartherD.ifBobwalkedfarther22.Youdidn’tletmedrive.Ifwe＿＿＿＿inturn,you＿＿＿sotired.

A.drove；didn’tgetB.drove；wouldn’tget

C.weredriving；wouldn’tget

D.haddriven；wouldn’thavegot

23.Withoutelectricityhumanlife＿＿＿＿quitedifferenttoday.

A.isB.willbeC.wouldhavebeenD.wouldbe

24.Oh,Janne,you’vebrokenanotherglass.Youought＿＿＿＿whenyouwashedit.

A.becarefulB.tocare

C.havecaredD.tohavebeencareful25.I＿__oftengofishingwhenIlivedinthecountryside.

A.shouldB.wouldC.couldD.might

26.He＿＿＿＿＿＿ratherstayathomethangotothecinemawithyou.

A.shouldB.mightC.wouldD.hadbetter

27.It’shightimewe＿＿＿＿＿tothetheater.

A.willB.shallC.aregoingtoD.went

28.——CouldIuseyourtelephone?

——Yes,ofcourseyou＿＿＿＿＿＿＿＿＿.

A.couldB.willC.canD.might

29.It’sstrangethatthey＿＿＿＿＿nothingaboutthismatter.

A.knowB.wouldknowC.knowsD.knew

30.Iwishyou＿＿＿＿＿＿gowithmetomorrow.

A.willB.wouldC.shallD.can

31.——DoyoustillrememberthedaywhenwewenttotheGreatWall?

——Ican’trememberitwell,but＿＿＿＿＿＿sometimelastautumn?

A.mightitbeB.couldithavebeen

C.coulditbeD.mustithavebeen

32.——Ican’tgetthroughtothegeneralmanager’sofficeanyhow.

——Thelineisbusy.Someone＿＿thetelephone.

A.mustuseB.uses

C.musthavebeenusingD.mustbeusing

33.Hesuggestswe＿＿＿＿＿＿tothecinemaatonce,otherwisewewillbelate.

A.mustgoB.goC.willgoD.wouldgo

34.Whenapencilispartlyinaglassofwater,itlooksasif＿＿＿＿.

A.breaksB.hasbroken

C.werebrokenD.hadbeenbroken

35.Thegeneralorderedthatthethief＿＿＿＿.

A.bepunishedB.wouldpunish

C.wouldbepunishedD.shouldpunish

36.IfonlyI＿＿＿＿＿howtooperateacomputerasyoudo!

A.hadknownB.wouldknow

C.shouldknowD.knew

37.Itissurprisingthathe＿＿＿＿atthemeeting.

A.wasB.beC.isD.were

38.Ifyou＿＿＿＿waitamoment,I’llgoandfindourmanager.

A.canB.shouldC.willD.must

39.——Doyouthinkhewilldomeafavor?

——AsfarasIknow,heisthelastonetohelpothers.He＿＿＿＿bepreparedtogiveyouahand,though.

A.mightB.mustC.canD.should

40.EventhoughI’dhurtmyleg,I＿＿＿＿＿＿swimbacktotheriverbank.

A.couldB.mightC.hadtoD.wasableto

41.You＿＿＿＿＿＿＿gotothepartyifyoudon’tfinishyourhomeworkfirst.

A.won’tB.don’tC.oughtn’tD.shan’t

42.——Itisrathercoldhere.Shallwelightafire?

——No,we＿＿＿becausethingsareeasytocatchfire.

A.won’tB.can’tC.mustn’tD.needn’t

43.I＿＿＿＿＿＿ProfessorJoneshadtaughtmethisquestion.

A.believeB.deeplythinkC.wishD.suppose

44.Thechairmanrequestedthat＿＿＿＿＿＿＿.

A.themembersstudiedtheproblemmorecarefully

B.theproblemsweremorecarefullystudied

C.theproblemscouldbestudiedwithmorecare

D.themembersstudytheproblemmorecarefully

45.I＿＿＿＿＿＿itagain.

A.wouldlikeyoutoread

B.wouldlikethatyouread

C.wouldlikeyoureading

D.wouldlikeyouread46.Ifyoureallywantyourselftobeingoodhealth,youmust＿＿＿always＿＿＿somuch.

A.not；besmokingB.not；havesmoked

C.not；tosmokeD.benot；smoking

47.IfI＿＿＿you,I＿＿＿＿moreattentiontoEnglishidiomsandphrases.

A.was；shallpayB.am；willpay

C.wouldbe；wouldpayD.were；wouldpay

48.“Wouldyouhavetoldhimtheanswerhaditbeenpossible?”

“Iwouldhave,butI＿＿＿＿sobusythen.”

A.hadbeenB.wereC.wasD.wouldbe

49.Hehadanexpressionofresentment（不高興）,asifMartin＿＿＿afoolofhim.

A.hadmadeB.makesC.madeD.wouldmake

50.＿＿＿＿thefog,weshouldhavereachedourschool.

A.BecauseofB.InspiteofC.IncaseofD.Butfor

51.Therewasahalfsmileonhisfacewhichsuggestedthathe＿＿＿＿happytohavegivenhislifeforhiscountry.

A.wasB.shouldbeC.wouldbeD.were

52.Weallagreedtohersuggestionthatwe＿＿＿＿＿＿totheGreatWallforsightseeing(觀光).

A.willgoB.goC.shallgoD.shouldhavegone

53.Youmustbeastudent,＿＿＿＿＿＿＿＿you?

A.wasn’tB.areC.mustn’tD.aren’t

54.Theyoungmaninsistedthathe＿＿＿＿＿nothingwrongand＿＿＿free.

A.did；setB.haddone；shouldbeset

C.do；besetD.haddone；mustbeset

55.Withoutyourhelp,I＿＿＿＿theexamlastterm.

A.failedinB.wouldhavefailed

C.wouldn’tpassD.wouldfail參考答案及解析

1.C。will在此表示“應(yīng)諾”。

2.B。MayI...?中的may用以表示“允許、許可”。

3.A。shall用于第二、三人稱的肯定句或否定句，表示說話人的意愿，有“命令、警告、威脅、強制、允諾、決心”之意。

4.C。may表示“允許”?；卮餸ay引起的問句，肯定式一般用Yes,ofcourse.／Yes,certainly.／Sure.／Yes,youmay.否定式用No,youmustn’t.

5.A。needn’t表示“不必要”；mustn’t表示“禁止”；wouldn’t表示“拒絕”。

6.A。can表示“可能性”，通常用于否定句或疑問句中，且有時還帶有“驚奇、不相信”等感情色彩。

7.B。must表示說話人的主觀愿望，而haveto多表示客觀需要。

8.D。wouldhavedone表示對過去已發(fā)生的事情的推測，表示“可能……”。

9.B。shouldn’thavedone表示“過去本來不應(yīng)該做某事而事實上已經(jīng)做了”。

10.D。should／shouldnot＋do，表示“（現(xiàn)在）應(yīng)該／不應(yīng)該……”。

11.B。Let’sdosth.表示“建議做某事”，含聽話一方在內(nèi)，故用shallwe。如果用Letusdosth.結(jié)構(gòu)，則用willyou?表示請求對方允許。

12.A。情態(tài)動詞dare的過去式為dared，常用于否定句、疑問句及條件句中，沒有人稱和數(shù)的變化，否定式是在dare后接not，再接動詞原形。dare作為實義動詞時，有人稱和數(shù)的變化，構(gòu)成否定句時，前要加助動詞，后接帶to或不帶to的動詞不定式。13.D。need作為情態(tài)動詞，一般用于否定句、疑問句及條件句中，后接動詞原形。表示“現(xiàn)在不必干某事”,用neednotdosth.；表示“過去不必干某事”，用neednothavedone。need作為實義動詞,與其它動詞用法相同，用于否定句或疑問句要加助動詞。

14.C?！癿usthavedone”結(jié)構(gòu)，表示對過去發(fā)生情況的肯定推測。

15.B。can’thavedone，表示對過去發(fā)生情況的否定推測，意為“不可能已經(jīng)……”。

16.B。musthavedone表示對過去發(fā)生情況的肯定推測，句中帶有明確的過去時間狀語，故附加疑問句用“didn’tthey”。17.C。should／ought