高中英語語法-《情態(tài)動詞與虛擬語氣》教學(xué)案

一、情態(tài)動詞的語法特征

(1)情態(tài)動詞不能表示正在發(fā)生或已經(jīng)發(fā)生的事情，只表示期待或估計某事的發(fā)生。

(2)情態(tài)動詞除ought和have外，后面只能接不帶to的不定式。

(3)情態(tài)動詞沒有人稱，數(shù)的變化。

(4)情態(tài)動詞沒有非謂語形式，即沒有不定式、分詞、動名詞等形式。二、虛擬語氣用來表示說話人的主觀愿望或假想，所說的是一個條件，多半不是事實，或與事實相反。高考重點要求：1、情態(tài)動詞的基本用法2、情態(tài)動詞表示推測的語義差別3、情態(tài)動詞后接不定式完成體的不同意義4、虛擬語氣中情態(tài)動詞的用法情態(tài)動詞(一)情態(tài)動詞在一般時否定句中的用法can't(cannot)表示“不可能”，maynot表示“不可以”“可能不”，mustn't(mustnot)表示“一定不要”，“不許可”，needn't(neednot)表示“不必”，darenot＋動詞原形表示“不敢”。Hecan'tknowthenews.Hemaynotsleepnow.Youmustn'tcriticizeherinthatway.Youneedn'tcometomorrow.Hedarednotmeethisparents.（二）can，may，must三者用法比較can，may，must是三個最重要的情態(tài)動詞1.can，may，must的肯定句Youmayeatlunch，butyoumustwashyourhands.你可以吃飯，但是你必須洗手。（1）can表示能力；能，會Shecanrunfast，butIcan't.她很會跑，但是我不會。表示可能；能夠Icangetthereintenminutes.我十分鐘之后就可以到那兒。（表示一種可能性）表示允許；許可Youcanusethisdictionary.你可以用這本字典。can和beableto比較can只有現(xiàn)在式和過去式，而beableto可以用于各種時態(tài)。can（could）表示能力時，可用beableto代替。Ican（=amableto）payforthebook.

我買得起那本書。Hewillbeabletotellyouthenewssoon.

他很快就能告訴你消息了。Shehasbeenabletocometoschool.

她已經(jīng)能去學(xué)校了。（2）may表示請求、許可MayIborrowyourpen？我可以借你的鋼筆用一用嗎？可能、或許TomorrowImaygoshopping.明天，我可能（或許）去商店買東西。Hemightbeournewteacher.他或許是我們的新老師。（3）must必須、應(yīng)該（表示有做某一動作的必要或義務(wù)）Youmustbuyaticket.你必須買一張票。一定、準是（表示有把握的判斷或推測，一般只用于肯定句中）Hemustbeournewteacher.他肯定是我們的新老師。表示推測的用法can,could,may,might,must皆可用來表示推測，其用法如下：could,might表示推測時不表示時態(tài)，其推測的程度不如can,may。can,could用于否定句和疑問句中。句型：主語+can't,couldn't+be+v-ing．（否定句）Can,Could+主語+be+v-ing．（疑問句）Theycan'tbecleaningtheroomnow．他們現(xiàn)在不可能在打掃房間。may,might,must用在肯定句中。句型：主語+may,might,must+be+動詞-ing（表示對現(xiàn)在發(fā)生動作的推測）Hemustbesleeping.他現(xiàn)在肯定在睡覺。must/can't…+have+過去分詞則指對過去已發(fā)生的事進行推測。Theroadiswet.Itmusthaverainedlastnight.地是濕的；昨天晚上肯定下雨了。Thereisn'tanywaterontheroad.It(can't)couldn'thaverainedlastnight.Youmusthaveseenthefilm,______________you?(三)haveto的用法1.have（has）to+動詞原形have（has）to后面要用動詞原形。當主語為第三人稱單數(shù)時用hasto，當句子是過去時用hadto。Wehavetoleavenow.HehastoworkonSunday.IhadtodomyhomeworklastSunday.2.haveto的否定句句型：主語+don't（doesn't,didn’t,willnot）haveto+動詞原形Youdon'thavetowalksofast.Hewillnothavetobuyanewcoatnextyear.3.haveto的疑問句你現(xiàn)在必須學(xué)數(shù)學(xué)嗎？___________________________________________.Yes，I__________________.No，I________________（haveto）。他非要問那個問題嗎？Didhehavetoaskthequestion？Yes，hedid.No，hedidn't（haveto）4.must與haveto比較must側(cè)重于個人意志和主觀上的必要，haveto側(cè)重于客觀上的必要。如果用于過去時態(tài)或?qū)頃r態(tài)時，則要用haveto的相應(yīng)時態(tài)來代替must。但must可用于間接引語中表示過去的必要或義務(wù)。Mybrotherwasveryill，soI_____________callforthedoctorinthemiddleofthenight.Ihaven'tgotanymoneywithme，soI'llhavetoborrowsomefrommyfriend.Hesaidthatthey__________workhard.他說他們必須努力工作。(四).usedtodosth的用法注意其否定句和疑問句的結(jié)構(gòu)。Thereusedtobealotoftreeshere,____________________?虛擬語氣虛擬語氣表示說話人的意愿、假設(shè)、猜測或建議。虛擬語氣不表示客觀存在的事實，謂語動詞用特殊的形式表示虛擬語氣。一、掌握虛擬語氣的四種主要形式（1）條件從句+主句（2）幾個常用虛擬語氣的句型（3）wish,asif及ifonly的虛擬形式（4）Itistimethat的虛擬形式二、注意虛擬語氣的三種活用現(xiàn)象（1）含蓄條件句（2）時間錯綜句（3）虛實錯綜句條件從句+主句時間謂語動詞的虛擬形式從句主句現(xiàn)在動詞過去式（be多用were）would/should/could/might+動詞原形過去had+過去分詞would/should/could/might+have+過去分詞將來動詞過去式或should/wereto+動詞原形would/should/could/might+動詞原形1.Therice______ifyouhadbeenmorecareful.A.wouldnotbeburningB.wouldnotburnC.wouldnothaveburntD.wouldnotburnt2.Ifmylawyer____herelastSaturday,he______mefromgoing.A.hadbeen;wouldhavepreventedB.hadbeen;wouldpreventC.were;wouldpreventD.were;wouldhaveprevented3.Ididn’tseeyoursisteratthemeeting.Ifshe______shewouldhavemetmybrother.A.hascomeB.didcome C.cameD.hadcome4.______forthefreetickets,Iwouldnothavegonetothefilmssooften.A.IfitisnotB.WereitnotC.HaditnotbeenD.Iftheyhavenot5.Youdidn’tletmedrive.Ifwe______inturn,you______sotired.A.drove;didn’tgetB.drove;wouldn’tgetC.weredriving;wouldn’tgetD.haddriven;wouldn’thavegot6.Ifshehadworkedharder,she______.A.wouldsucceedB.hadsucceededC.shouldsucceedD.wouldhavesucceed7.—Ifhe______,he______thatfood.—Luckilyhewassenttothehospitalimmediately.A.waswarned;wouldnottakeB.hadbeenwarned;wouldnothavetakenC.wouldbewarned;hadnottakenD.wouldhavebeenwarned;hadnottaken8.Ifit______tomorrow,theywouldnotgotherebybike.A.willrainB.rains C.wouldrainD.shouldrain9.______itraintomorrow,wewouldhavetoputoffthevisittotheYangpuA.WereB.Should C.WouldD.Will10.IfI______you,Iwouldnotdoit.A.amB.were C.shallbeD.being（一）、含蓄條件句含蓄條件句就是虛擬條件暗含在短語或上下文中，從句不表現(xiàn)出來。這時，必須根據(jù)句中表述的意義以及某些特定的信息詞，并依據(jù)前文所列舉的四種現(xiàn)象，來判斷此時須采用的形式。1.Withoutelectricity,humanlife______quitedifferenttoday.A.isB.willbeC.wouldhavebeenD.wouldbe2.YesterdayJanewalkedawayfromthediscussion.Otherwise,she______somethingshewouldregretlater.A.hadsaidB.saidC.mightsayD.mighthavesaid（二）、時間錯綜句從句與主句或上下文所表述的時間不一致。在這種情況下，我們切不可照搬某種形式，而應(yīng)該按照句中所表述的時間關(guān)系，再選擇相應(yīng)的虛擬形式。例如：Ifyouhadworkedhardyesterday,youwouldbetirednow.1.Iftheflowerhadbeenwatered,it______now.A.wouldn’tdieB.isdeadC.hadbeendeadD.willnotdie2.Ifhistelevisionsethadnotbeenstolenyesterday,he______TVnow.A.wouldwatchB.wouldhavewatchedC.wouldbewatchingD.iswatching幾個常用虛擬語氣的句型1.動詞+賓語從句一個堅持：insist;兩個命令：order,command;三個建議：suggest,propose,advise;四個要求：desire,demand,ask,requireIproposethatwe(should)setadeadlineforhandingintheplans.Isuggestthatwe(should)setoffatonce.Iinsistedthatwe(should)decidewhattodowithhim.虛擬語氣形式：(should)+動詞原形2.Itis(was)+上述動詞的過去分詞+that主語從句Itisdemandedthathe(should)leaveatonce.Itisrequestedthatshe(should)giveaperformanceattheparty.3.Itis(was)+important/necessary/better/strange/surprising/natural/possible/apity/nowonder+that主語從句Itisbestthathe(should)setoffatonce.Itisimportantthateverybody(should)betoldallthefacts.虛擬語氣形式：(should)+動詞原形4.order等+be+表語從句Myadviceisthatwe(should)sendforadoctor.Oursuggestionisthatyou(should)befirsttogo.Hisonlyrequestisthatyou(should)givehimmoretime.5.order等+同位語從句Doyouknowtheorderthatyou(should)keepwatch?上述結(jié)構(gòu)中常用的名詞有：suggestion,order,proposal,plan,idea,command,request等。虛擬語氣形式：(should)+動詞原形1.Iinsistthatadoctor______immediately.A.hasbeensentforB.sendsforC.willbesentforD.besentfor2.Itissuggestedthatthejob______doneinanotherway.A.wasB.wastobeC.beD.mustbe3.Hehadanideathatwe______bybike.A.shallgoB.goC.wentD.wouldgo4.Mysuggestionisthatthemeeting______offtilltomorrow.A.toputB.beputC.shouldputD.beputting5.Theyoungmaninsistedthathe_____nothingwrongand_____free.A.did;setB.haddone;shouldbesetC.do;besetD.does;wouldbeset6.Itisnecessarythatyou______presentatthediscussion.A.willbeB.areC.shouldbeD.wouldbe7.Thebossgaveordersthatthework______atonce.A.willbestartedB.mustbestartedC.bestartedD.shouldstart8.Theguardthereinsistedthateverybody______therules.A.obeysB.obeyC.willobeyD.wouldobeywish,asif以及ifonly的虛擬形式：這幾個詞（詞組）表虛擬時，其后所用的虛擬形式與條件從句基本相同，即此陳述語氣中的時態(tài)后退一個時態(tài)。隨“時”變化的幾種用法：

時間謂語動詞虛擬語氣wish/asif/asthough/ifonly/wouldrather現(xiàn)在動詞過去式（be多用were）過去had+過去分詞將來would+動詞原形1.IwishI______youyesterday.A.seenB.didseeC.hadseenD.weretosee2.Whenapencilispartlyinaglassofwater,itlooksasifit______.A.breaksB.hasbrokenC.werebrokenD.hadbeenbroken3.I’dratherthatyou______thereyesterdayand______againnextweekend.A.went;shouldcomeB.shouldgo;hadcomeC.hadgone;cameD.go;come4.Thetwostrangerstalkedasifthey______friendsforyears.A.shouldbeB.wouldbe C.havebeenD.hadbeen5.—Iblamedheryesterday.—Iwouldratheryou______that.A.didn’tdoB.hadn’tdone C.wouldn’tdoD.shouldn’tdo6.—Heisaverybraveman.—Yes.IwishI______hiscourage.A.have B.had C.willhaveD.wouldhaveItistimethat的虛擬形式Itistimethat…Itishightimethat…Itisabouttimethat…Itistime還可以有其他句型形式，需注意辨析：Itistime(forsb.)todosth.Itistimeforsth./doingsth.Itisthefirsttimethat(從句用陳述語氣的現(xiàn)在完成時)1.Itishightimeyou______thebus.A.hadcaught B.caughtC.willcatch D.catch2.It’sabouttimehe______todothework.A.begins B.willbeginC.begin D.began3.It’shightimethatwe___toschool.A.wouldgo B.wentC.go D.willgo4.Itistimewe___upourresults.A.sum B.summedC.willsum D.wouldsum鞏固練習(xí)1.—Isn'tthatAnn'shusbandoverthere?—No,it_______behim.I'msurehedoesn'twearglasses.A.can't

B.mustnot C.won't

D.maynot2.Youtothemeetingthisafternoonifyouhavesomethingimportanttodo.A.needn'ttocome B.don'tneedcomeC.don'tneedcoming D.needn'tcome3.Heyoumorehelp,eventhoughhewasverybusy.A.mighthavegivenB.mightgiveC.mayhavegivenD.maygive4.Thereasonwhytheyleavewasn'texplainedtous.

A.had B.hadto C.must D.might5.Isearchedformywalletanditwasn'tthere.IthoughtIitathome.

A.left B.haveleft C.mighthaveleft D.couldhaveleft6.I________asleepbecauseittookmealongtimetorealizethatthetelephonewasringing.

A.couldhavefallen B.shouldhavefallenC.musthavefallenD.mustn'thavefallen7.Theonlythingthatreallymatterstothechildrenishowsoontheyreturntotheirschool.

A.can B.must C.haveto D.oughtto8.Iwanttogotothechemist's,butyougowithme.

A.neednot B.mustnot C.need D.can’t9.Whatwegetseemsbetterthanwhatwehave.

A.can B.could C.can't D.couldn't10.—Mygoodness!I'vejustmissedthetrain.—That'stoobad.Iamsureyouit,ifyouhadhurried.A.couldhavecaught B.hadcaughtC.wouldcatchD.couldcatch11.Look!Whatyou'vedone!Youmorecareful.

A.maybe B.hadto C.shouldhavebeen D.wouldbe12.Irepeatthequestion?

A.Shall B.Will C.Doyouwantthat D.Do13.ProfessorLi,manystudentswanttoseeyou.theywaithereoroutside!

A.Do B.Will C.Shall D.Are14.Youreadthatbookifyoudon'twantto.

A.haven't B.can't C.mustn't D.needn't15.Johnny,youplaywiththeknife;youhurtyourself.

A.won't…can't B.can't…shouldn'tC.shouldn't…mustD.mustn't…may16.—Therewerealready5peopleinthecar,buttheymanagedtotakemeaswell.—Itacomfortablejourney.

A.can'tbe B.shouldn'tbe C.couldn'thavebeen D.mustn'thavebeen17.Tomoughtnottomeyoursecret,buthemeantnoharm.

A.havetold B.tell C.betelling C.havingtold18.Everyoneishere.westartthemeeting?

A.Can B.Must C.Should D.Shall19.Iparkedmycarrightherebutnowit'sgone.It.

A.mustbestolen B.maybestolen

C.musthavestolen D.musthavebeenstolen20.Hetheworkyesterday,buthedidn't.

A.musthavefinished B.needhavefinishedC.finishedD.shouldhavefinished21.Hedidnotpasstheexamination.Asagoodstudent,he.

A.mustn'thavefailed B.maynothavefailedC.needn'thavefailedD.shouldn'thavefailed22.itbetruethatAlbertpassedthetestingeography?

A.May B.Should C.Could D.Would23.Youleadahorsetothewaterbutyounotmakeitdrink.

A.will…can B.may…can C.may…dare D.dare…can24.—Mustwefinishthecompositioninclass?—No,you.

A.needn't B.mustn't C.won't D.shouldn't25.Hereyeswerered.She.

A.mustcryB.mustbecriedC.musthavebeencryingD.maycry26.Maryhisletter;otherwiseshewouldhaverepliedbeforenow.

A.hasreceivedB.mustreceiveC.couldn'thavereceivedD.shouldn'thavereceived27.ItoldSallyhowtogethere,butperhapsIforher.

A.hadtowriteitoutB.musthavewrittenitoutC.shouldhavewrittenitoutD.oughttowriteitout28.Hedescribedthetownasifheithimself.

A.hadseen B.hasseen C.saw D.sees

29.Mostinsuranceagentswouldratheryouanythingaboutcollectingclaimsuntiltheyinvestigatethesituation.

A.do B.don’t