Unit2HealthyeatingLearningaboutLanguage1.Learnthemodalverbs:oughtto/haveto.2.Understandthedifferentusagesofthemodalverbs:hadbetter/should/oughtto,shall/should/oughtto,dare/need,must/haveto3.Developstudents’interestinGrammarLearning.LearningaimsFirstwealthishealth.

Q1:Whatshould/shouldn’t

wedotokeephealthy?Q2:Whatkindoffoodmustweeattobestrong?Q3:Whatoughtwetoeattostayslim?

Q4:Whatmodalverbs

haveyoulearned?Can,could

May,might

Must/havetoNeed,

Dare

Will/wouldShall/should/oughttoLeading-inModalverb(2)一、oughtto

oughtto用于表示“想必會”“應(yīng)當(dāng);應(yīng)該”(語氣較must弱)：1.他們想必現(xiàn)在已到那兒了。

Theyoughttobetherebynow.2.他最好不要抽煙了。Heoughttostopsmoking.

多數(shù)情況下，oughtto可與should互換使用。oughtto的反意疑問句用shouldn’t替代。注意哦hadbetter,should,oughtto三者均表示建議，意為“應(yīng)該”，“應(yīng)當(dāng)”或“最好做……”。三者的語氣程度為漸強。hadbetter指一般性的建議。should&oughtto含義相近，常可互換。區(qū)別在于:oughtto常指特殊情況下的“應(yīng)當(dāng)”；should則指一般情況。最弱【辨析】Yououghttohelphimbecauseheisintroublenow.(語氣強)Youshouldhavearestafterfinishingyoursports.（一般性建議）Yououghttocallthepolicewhenyoufindsomethingwronginyourhouse.(語氣較強)Heshouldtakecareofthebabiestonight.（一般情況）有命令意味1.YououghttohavehelpedhimwithhisEnglish,____?A.won’tyouB.cannotyouC.shouldn’tyouD.wouldn’tyou2.Asasoldier,you____todoastheofficertellsyou.A.oughtB.shallC.shouldD.will【即學(xué)即練】CA二、havetohaveto表示客觀需要去做的事情，意為“必須，不得不”。有時態(tài)、人稱和數(shù)的變化，其否定形式和疑問形式需要借助助動詞do。Ihavetoleaveheralone.（肯定句）我不得不留她一個人。Youdon’thavetobealone.(否定句)你不需要被孤立一人。Hehadtobethereatonce.(過去式)他得立刻趕到那兒。haveto的否定形式為don’thaveto,表示“沒有義務(wù)或沒有必要做某事”，意為“不必”，常可以回答must提問的一般疑問句。而must的否定式mustn’t表示“禁止”。—MustIhandinthepapertomorrow?—No,youneedn’t/don’thaveto.【即學(xué)即練】

—Whatdoyouthinkwecandoforouragedparents?—You______doanythingexcepttobewiththemandbeyourself.A.don’thavetoB.oughtn’ttoC.mustn’tD.can’tANeedIdo…?Yes,youmust.No,youneedn’t.情態(tài)動詞實義動詞dare肯：daretodoneed否，疑needn’tdo(don’t)needsth.(don’t)needtodo肯：must,haveto,oughtto,should三.dare&need否，疑，條

darenotdo否,疑don’tdaretododon’tdaredo注意對need問句的回答:—Need

Ifinishtheworktoday?—Yes,__________.No,___________.No,________________.youmustyouneedn’tyoudon’thaveto同mustneedn’t對其他情態(tài)動詞的回答:

—ShallItellJohnaboutit?—No,you_____________.—Mustwedoitnow?—No,you_____________.(don’thaveto)needn’t(don’thaveto)needn’t【拓展】情態(tài)動詞+havedone的用法1.musthavedone

表示對過去情況進行肯定的推測，意為“過去一定做過某事”。2.couldhavedone

表示本來過去能夠做而實際未做。3.shouldhavedone

表示本來過去應(yīng)該做而實際未做。4.can(could)not/neverhavedone

表示對過去事情的否定推測，意為“肯定不，絕不可能”。5.needn’thavedone

表示本不必要做某事而實際做了。【高考鏈接】(2015·天津高考)I

haveworriedbeforeIcametothenewschool,formyclassmateshereareveryfriendlytome.A.mightn’t B.mustn’t C.needn’t D.couldn’t【解題關(guān)鍵】句意:來新學(xué)校前我本沒有必要擔(dān)心的,因為這里的同學(xué)都對我很友好。needn’thavedonesth.本沒有必要做某事。1.Ithoughtyou_____likesomethingtoread,soIhavebroughtyousomebooks.A.mayB.mightC.wouldD.must2.Whereismypen?I____it.A.mightloseB.wouldhavelostC.shouldhavelostD.musthavelostBDClassexercises3.Ididn’thearthephone.I___asleep.A.mustbeB.musthavebeenC.shouldbeD.shouldhavebeen4.—Therewerealreadyfivepeopleinthecar,buttheymanagedtotakemeaswell.—It____acomfortablejourney.A.can’tbeB.shouldn’tbeC.mustn’thavebeenD.couldn’thavebeenBD5.It’sseven.Jack____behereatanymoment.mustB.needC.shouldD.could6.—IsJohncomingbytrain?—Heshould,buthe_____not.Helikesdriving.A.mustB.canC.needD.mayCD7.Ithasbeenannouncedthatcandidates(候選人)______remainintheirseatsuntilallthepapershavebeencollected.A.canB.willC.mayD.shall8.—Iheardhewentskiinglastyear.—It_____truebecausetherewaslittlesnowthere.A.maynotbeB.won’tbeC.couldn’tbeD.mustn’tbeDC9.—Didthetrainarriveintime?—No.It_______twohoursago.A.musthavearrivedB.oughttohavearrivedC.mustarriveD.oughttoarrive10.—MustIdrivetohishouseandpickupthechildren?

—No,________.

A.youshouldn’t

B.youmightnot

C.youneedn’t

D.youmustn’tBC11.Wedidn’tseeTomatthemeetingyesterday.He____it.

A.mustn’thaveattended

B.cannothaveattendedC.needn’thaveattended

D.wouldhavenotattendedBC12.You________suchalongcomposition.Theteacheronlyaskedfor300words.Youhavewritten600words.A.mustn’thavewrittenB.couldn’thavewrittenC.