need,must用法及练习

1、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) .Thesoupneedsalt.2) .Theydonneedafraidanymore.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：.主动形式的动名词doing具有被动的含义；.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) .Your

2、carneedsrepairing.=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.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；.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.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meettheneedso硒足的需要)。例如：13) .There'snoneedf

4、oryoutotryagain.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'thaveboughtsomuchwineonlyfivepeoplecame.Heneedhavehurriedtothestation.Inthatcase,bewouldn'thavemissedthetrain.youneednothavesaidthatshould+have+done"意思是本来应该做某事，而

5、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.3. youshouldhavetoldmemust+have+done”表示对过去事情的肯定推测，译成幺定做过某事”，该结构只用于肯定句1. Itmusthaverainedlastnight,forthegroundiswet

6、.2. Youmusthavebeenmadtospeaktotheservant.must的用法1.must表示必须"、应该”。例如：Wemustprotectourenvironment.Everyonemustobeytherule.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：Youmustn'tspeaklikethat.Youmustn'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'或don'thaveto回答。而不用mustn&#

7、39;来回答。例如：MustIbehomebefore8o'clock?（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，意思是乙定"、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：Hemustbeathome.他准在家里。）Theremustbesomechildrenintheroom.（房间里准有些孩子。）2 .）对于现在动作的推测，我们用：must+be+

8、doing（行为动词），例如：Theymustbecleaningtheirroom.他们准是在打扫房间。）HemustbewatchingTV.（他准是在看电视。）3 .）对于过去事实的推测，我们用：must+have+i去分词,例如：Itmusthaverainedlastnight.（乍晚准是下雨了。）Ididn'thearthephon田Usthavebeenasleep.（我没有听到电话，我准是睡着了。）练习Choosetherightanswer.()1.Youanyhelp,doyou?A.don'tneedB.needn'tC.needD.doesn&#

9、39;tneed()2.-MustIstayattheofficethisafternoon?-No,you.A.don'tB.needn'tC.don'tneedD.can't()3.Tomgetupalittleearliertomorrow.A. needsB.needC.needtoD.needsto()4.Needthedoctorwithyoutonight?A.stayingB.stayC.staysD.tostay()5.Look!Yourshirtissodirty.ItA. need washing()6. The supply canA.

10、meet need ofC. meet the needs ofB. needtowashC.needswashingD.needwash'thedemand.B.meettheneedofD.meetneedsof().7.ThehospitalisA.ingreatneedofblood.B.ongreatneedofC.ingreatneedwithD.ongreatneedwith()8.Yourroomisfullofdust.It.A.needcleanB.needcleaningC.needtobecleanedD.needstobecleaned()9.Davidany

11、thingtodrink?A.Need,B.Needs,C.Does-needD.Do-need()10.Youtothemeetingtomorrowifyouhavesomethingimportanttodo.A.neednttocomeB.dontneedcomeC. dontneedcomingD.needntcome二.Fillintheblanksusinghaveto,havegotto,must,should,oughtto,hadbetter.1 .Younotgetdownuntilthebushasstopped.2 .TheybeencouragedtospeakEn

12、glishafterclass.3 .Youoftenwaitalongtimeforabus.4 .WegoandseeMarytomorrow,butIdontthinkwewill.5.Inotmissmytrain.6.Whentraveling,youtakecareofyourhealth.7.Insomepartsoftheworld,youboilthewaterbeforedrinkingit.1.1 fyouhaveastomachpain,youdrinkhotweaktea.9 .Younotswimimmediatelyafteraheavemeal.10 .Younotwakemeupwhenyoucomein.三Translate1 .他需要好好睡上一晚上。