(完整版)need,must用法及练习

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 need s salt.
2). They don’t need afraid any more.
3). Does he need any help?
2．need doing 与need to be done
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). The door needs painting.
= The door needs to be painted.
5). Your car needs repairing.
= Your car needs 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 need to take for the party?
7). Will we need to show our ID card?
8). I need to take good care of my sister.
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)．You needn't do it again．
10)．He needn't worry about it．
④．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 again?
12）—Need I stay here any longer?
—No, you needn’t.
—Yes, you must.
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) need of（急需）与meet the needs of(满足……的需要)。

例如：
13). There’s no need for you to try again.
14). The factory is in great need of funds.
“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”。

I needn't have bought so much wine—only five people came.
He need have hurried to the station. In that case, be wouldn't have missed the train. you need not have said that “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, you are too lazy. The work should have been finished yesterday.
2. Look, Tom is crying. I shouldn't have been 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 night, for the ground is wet.
2. You must have been mad to speak to the servant.
1.must 表示“必须”、“应该”。

例如：
①We must protect our environment.
②Everyone 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：
①You mustn’t speak like that.
②You 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mustn’t来回答。

例如：
①——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 have 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：
①He must be at home.(他准在家里。

）
②There 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：
①They must be cleaning their room.(他们准是在打扫房间。

）
②He must be watching TV.（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:
①It must have rained last night.(昨晚准是下雨了。

）
②I didn’t hear the phone. I must have been asleep.（我没有听到电话，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. need
D. doesn’t need
( ) 2. ---Must I stay at the office this afternoon? ---No, you .
A. don’t
B. needn’t
C. don’t need
D. can’t
( ) 3. Tom get up a little earlier tomorrow.
A. needs
B. need
C. need to
D. needs to
( ) 4. Need the doctor ________ with you tonight?
A. staying
B. stay
C. stays
D. to stay
( ) 5. Look! Your shirt is so dirty. It .
A. need washing
B. need to wash
C. needs washing
D. need wash
( ) 6. The supply can’t the demand.
A. meet need of
B. meet the need of
C. meet the needs of
D. meet needs of
( ).7. The hospital is blood.
A. in great need of
B. on great need of
C. in great need with
D. on great need with
( ) 8. Your room is full of dust. It .
A. need clean
B. need cleaning
C. need to be cleaned
D. needs to be cleaned
( ) 9. David anything to drink?
A. Need,…\
B. Needs,…\
C. Does…need
D. Do…need
( ) 10. You to the meeting tomorrow if you have something important to do.
A. needn’t to come
B. don’t need come
C. don’t need coming
D. needn’t come
二.Fill in the blanks using have to, have got to, must, should, ought to, had better.
1.You _____________ not get down until the bus has stopped.
2.They _____________ be encouraged to speak English after class.
3.You often _____________ wait a long time for a bus.
4.We _____________ go and see Mary tomorrow, but I don’t think we will.
5.I _____________ not miss my train.
6.When traveling, you _____________ take care of your health.
7.In some parts of the world, you _____________ boil the water before drinking it.
8.If you have a stomach pain, you _____________ drink hot weak tea.
9.You _____________ not swim immediately after a heave meal.
10.You _____________ not wake me up when you come in.
三．Translate
1.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. ABDBC 6-10. CADCD。