need,must用法及练习

1、need用法一用作实义动词1. need sth.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) . The soup n eed salt.2) . They don nbed afraid any more.3) . Does he n eed any help?2. need doing 与 need to be done通常物做主语，n eed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) . The door n eeds painting.=

2、The door n eeds to be pain ted.5) . Your car n eeds repairi ng.=Your car n eeds to be repaired.3. need to do sth.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) . What do we n eed to take for the party?7) . Will we n eed to show our ID card?8) . I n eed to take good care of my sister.二. 用作情态动词 .没有人称和数的变

3、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。 .变为否定句时只需在情态动词之后加n ot。9) . You neednt do it again10) . He neednt worry about it. .变为疑问句时只需将情态动词提到主语的前面。例如：11) . Need I type this letter aga in?12) Need I stay here any Ion ger?No, you needn t.Yes, you must.三. 用作名词

4、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) need of (急 需) 与meet the needs o满足的需要)。例如：13) . There s no need for you to try again.14) . The factory is in great n eed of fun ds.need+have+done ”表示本来需要做某事而没有做。“ neednt+have+done ”则表示本来不需要做某事而做了。I n eed nt have bought so much wine only five people cam

5、e.He n eed have hurried to the statio n. In that case, be would nt have missed the trai n.you n eed not have said that“ should+have+done 意思是本来应该做某事，而实际没做。”“ shouldnt+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, you are too lazy. The work should have been finished yesterday.2. Look, Tom is cryin g

6、. I should nt have bee n so harsh on him.3 you should have told me“ 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. It must have rained last ni ght, for the grou nd is wet.2. You must have bee n mad to speak to the serva nt.must的用法1. must表示“必须”、“应该”。例如： We must protect our en vir onment. Every one

7、 must obey the rule.2. must的否定形式must not表示“不应该”、“禁止”、“不准”。语气比较强烈。例如： You mustn t speak like that. You mustn t be late for school.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 t have to来回答。 而不用must nt来回答。例如：Must I be home before 8 o clock?（8 点之前我必须回家吗？）Yes, you must. No, you needn t./No, you don t ha

8、ve to.（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： He must be at home.（ 他准在家里。） There must be some children in the room.（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： They must be cleaning their room.（他们准是在打扫房间。） He must be watching TV

9、.（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： It must have rained last night.（昨晚准是下雨了。） I didn t hear the phone. Imust have been asleep.（我没有听至U电话，我准是睡着了。）练习一. Choose the right answer. （）1. You any help, do you?A. don t need B. needn t C. needD. doesn t need()2. -Must I stay at the office this af

10、ternoo n?-No, youA. don t B. needn t C. don t need D. can t()3. Tom get up a little earlier tomorrow.A. n eedsB. n eed C. n eed toD. n eeds to()4. Need the doctorwith you toni ght?A. stayi ng B. stayC. stays D. to stay()5. Look! Your shirt is so dirty. It .A. n eed wash ing()6. The supply canA. meet

11、 n eed ofB. n eed to wash C. n eeds wash ing D. n eed wash the dema nd.B. meet the n eed ofC. meet the n eeds ofD. meet n eeds of().7. The hospital isA. in great n eed ofC. in great n eed withblood.B. on great n eed ofD. on great n eed with()8. Your room is full of dust. ItA. n eed clea nC. n eed to

12、 be clea nedB. n eed clea ningD. n eeds to be clea ned()9. Davidan yth ing to drink?A. Need,B. Needs, - C. Does need D. Do need()10. You to the meeti ng tomorrow if you have someth ing importa nt to do.A. needn t to comeB. don t need comeC. don t need comingD. needn t come二. Fill in the blanks using

13、 have to, have got to, must, should, ought to, had better.1. Younot get dow n un til the bus has stopped.2. Theybe en couraged to speak En glish after class.3. You ofte nwait a long time for a bus.4. Wego and see Mary tomorrow, but I don t think we will.5.1not miss my trai n.6.Whe n traveli ng, youtake care of your health.7.ln some parts of the world, youboil the water before drinking it.8.If you have a stomach pain, youdrink hot weak tea.9. Younot swim immediately after a heave meal.10. Younot wake me up whe n you come in.三. Tran