(完整版)need-must用法及练习

need用法一．用作实义动词1．needsth.这是need最常见的用法之一，其后的宾语可以是名词，也可以是代词。如：1).Thesoupneedssalt.2).Theydon’tneedafraidanymore.3).Doesheneedanyhelp?2．needdoing与needtobedone通常物做主语，need后面可跟动名词作宾语，这种情况下应注意两点：①.主动形式的动名词doing具有被动的含义；②.该动名词可以改为其动词不定式的被动形式而句子的意义不变。例如：4).Thedoorneedspainting.=Thedoorneedstobepainted.5).Yourcarneedsrepairing.=Yourcarneedstoberepaired.3．needtodosth.作为实义动词，need后面需要接带to的动词不定式,表示有义务或责任去做某事。如：6).Whatdoweneedtotakefortheparty?7).WillweneedtoshowourIDcard?8).Ineedtotakegoodcareofmysister.二．用作情态动词①．没有人称和数的变化。不论主语是第几人称，不论主语是单数还是复数，情态都词都无形式变化；②．不能单独充当谓语。情态动词必须与一个实义动词一起构成复合谓语，并且这个实意动词要始终是动词原形。③．变为否定句时只需在情态动词之后加not。9)．Youneedn'tdoitagain．10)．Heneedn'tworryaboutit．④．变为疑问句时只需将情态动词提到主语的前面。例如：11).NeedItypethisletteragain?12）—NeedIstayhereanylonger?—No,youneedn’t.—Yes,youmust.三．用作名词need作为名词，含义为“缺乏，需要”；其复数表示“基本需要”。要掌握两个词组：in(great)needof（急需）与meettheneedsof(满足……的需要)。例如：13).There’snoneedforyoutotryagain.14).Thefactoryisingreatneedoffunds.“need+have+done”表示本来需要做某事而没有做。“needn't+have+done”则表示“本来不需要做某事而做了”。Ineedn'thaveboughtsomuchwine—onlyfivepeoplecame.Heneedhavehurriedtothestation.Inthatcase,bewouldn'thavemissedthetrain.youneednothavesaidthat“should+have+done”意思是“本来应该做某事，而实际没做。”“shouldn't+have+done”表示本来不应该做某事，而实际做了。含有指责对方或自责的含意。1.Tom,youaretoolazy.Theworkshouldhavebeenfinishedyesterday.2.Look,Tomiscrying.Ishouldn'thavebeensoharshonhim.3youshouldhavetoldme“must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，该结构只用于肯定句。1.Itmusthaverainedlastnight,forthegroundiswet.2.Youmusthavebeenmadtospeaktotheservant.must的用法1.must表示“必须”、“应该”。例如：①Wemustprotectourenvironment.②Everyonemustobeytherule.2.must的否定形式mustnot表示“不应该”、“禁止”、“不准”。语气比较强烈。例如：①Youmustn’tspeaklikethat.②Youmustn’tbelateforschool.3.在回答must的问句时，肯定形式用must来回答，但否定形式用needn’t或don’thaveto来回答。而不用mustn’t来回答。例如：①——MustIbehomebefore8o’clock?(8点之前我必须回家吗？)——Yes,youmust.No,youneedn’t./No,youdon’thaveto.（是，你必须。）（不，你不必。）4.must还可表示推测，意思是“一定”、“必定”，一般只用于肯定句中。分三种情况：1.）对于现在状态的推测，我们用：must+v.（状态动词或系动词），例如：①Hemustbeathome.(他准在家里。）②Theremustbesomechildrenintheroom.（房间里准有些孩子。）2.）对于现在动作的推测，我们用：must+be+doing（行为动词），例如：①Theymustbecleaningtheirroom.(他们准是在打扫房间。）②HemustbewatchingTV.（他准是在看电视。）3.）对于过去事实的推测，我们用：must+have+过去分词，例如:①Itmusthaverainedlastnight.(昨晚准是下雨了。）②Ididn’thearthephone.Imusthavebeenasleep.（我没有听到电话，我准是睡着了。）练习一．Choosetherightanswer.()1.You________anyhelp,doyou?A.don’tneedB.needn’tC.needD.doesn’tneed()2.---MustIstayattheofficethisafternoon?---No,you.A.don’tB.needn’tC.don’tneedD.can’t()3.Tomgetupalittleearliertomorrow.A.needsB.needC.needtoD.needsto()4.Needthedoctor________withyoutonight?A.stayingB.stayC.staysD.tostay()5.Look!Yourshirtissodirty.It.A.needwashingB.needtowashC.needswashingD.needwash()6.Thesupplycan’tthedemand.A.meetneedofB.meettheneedofC.meettheneedsofD.meetneedsof().7.Thehospitalisblood.A.ingreatneedofB.ongreatneedofC.ingreatneedwithD.ongreatneedwith()8.Yourroomisfullofdust.It.A.needcleanB.needcleaningC.needtobecleanedD.needstobecleaned()9.Davidanythingtodrink?A.Need,…\B.Needs,…\C.Does…needD.Do…need()10.Youtothemeetingtomorrowifyouhavesomethingimportanttodo.A.needn’ttocomeB.don’tneedcomeC.don’tneedcomingD.needn’tcome二.Fillintheblanksusinghaveto,havegotto,must,should,oughtto,hadbetter.1.You_____________notgetdownuntilthebushasstopped.2.They_____________beencouragedtospeakEnglishafterclass.3.Youoften_____________waitalongtimeforabus.4.We_____________goandseeMarytomorrow,butIdon’tthinkwewill.5.I_____________notmissmytrain.6.Whentraveling,you_____________takecareofyourhealth.7.Insomepartsoftheworld,you_____________boilthewaterbeforedrinkingit.8.Ifyouhaveastomachpain,you_____________drinkhotweaktea.9.You_____________notswimimmediatelyafteraheavemeal.10.You_____________notwakemeupwhenyoucomein.三．Translate1.他需要好好睡上一晚上。2.你需要理发了。3.我需要你查一下英语字典。4.你不必解释。5.我想要知道我们是否要带睡袋。6.我们不必在雨里站着。7.他昨天其实是不必去那儿的。8.你不必这么粗鲁。9.你一定是在开玩笑吧。10.她结婚时一定很年轻。11.我的妹妹准是在看电视现在。12.我本来不应该买这双鞋的。13．我本来需要去杭州的今年3月份。KEY:1-5.ABDBC6-10.CADCD