情态动词的语法特征

情态动词的语法特征
1）情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。

2）情态动词除ought 和have 外，后面只能接不带to 的不定式。

3）情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。

4）情态动词没有非谓语形式，即没有不定式，分词，等形式。

1、表示能力：can/could , be able to (+do)
able to 的区别：观察以下各句，可知can 只能用于和；be able to 可用于各种时态。

eg: ① I can /am able to speak English. 他能说英语。

② He could/ was able to eat four pieces of bread when he was young.
③ They will be able to finish the housework soon.
2）Can/could you+ 动原+其它？表示征求对方意见或提出请求，表示委婉语气，但在这个句型里could比can更委婉。

但要注意它的回答用can不用could.
Eg: ---Could you help me ?---Yes, I can.
2、表示许可：may/might, can/could. 但一定要注意：以may开头的疑问句的否定回答。

–Yes, you may. / No, you can’t = No ,you mustn’t.
3、表示必须、必要：must, have to 表示；needn’t 表示。

你必须完成这个工作。

1）观察以下句子，我们可知must表示说话人的；have to 表示。

Eg: ① I must go home. 我必须回家；
② He has to give up smoking because of badly cough. 因为咳嗽，他不得不戒烟。

2）观察以下句子，我们可知mustn’t表示,译为；don’t have to译为。

Eg: ① You mustn’t beat her. 你不准打她。

②–Must I finish my homework now?—Yes, you must ./ No, you needn’t=you don’t have to
-我必须现在完成作业吗？--是的，你必须完成。

/ 不，你不必了。

4、表示推测：must, can, could , may, might.
You run for hours, you must be very tired. 你跑了几个钟，你一定很累了。

② It can’t be John. He has gone to the UK. 不可能是John, 他已经去了英国。

③–Who can it be? ---It may/could/might be Jack. It looks like him.
--可能是谁呢？--可能是Jack, 看起来像他。

观察以上各句总结：肯定推测译为；否定推测译为；疑问推测有个译为；可能性推测用。

及时训练并归纳最常考情态动词的用法：
1、---Would you like to go fishing with me? ---Yes, / 。

2、---May I put these things here? ---Yes, / No,
3、---Must we hand in our homework today? ---Yes, / No,
4、---Look! Someone is coming. It be our class teacher. (用must/can/could/may/might填空)
be him. He has gone to Beijing.
many things here.—Do you know all these should _______ (付款) in US dollars? (pay)
2. — Shall we take a taxi? —No, we _______ . It’s not far from here.
A. can’t
B. mustn’t C, shouldn’t D. needn’t
3. —Whose T-shirt is this?—It be John's. It's much too small for him.
A. may
B. must
C. can't
D. shouldn't
4. —What should we do about the trash?—It (65) (必须带走) when you leave. (take)
1.+ 动词原形例：You must finish the work.
否定句：情态动词+not 例：He can not carry the box.
2.can “能力,许可” 例：He can swim now. （能够）
can’t =cannot =can not “不能” 例：He can’t swim now. (不能)
could ①could是“can的过去式” 例：He could swim three years ago.
②could还可以表示“客气委婉的语气或请求”，用在疑问句中。

回答时用can。

例：Could Jim lend me his bike? ------Yes, he can.
★can和be able to在表示“能力”上意思相同，差别不大。

can只有现在和过去两种形式，而be able to有更多的时态形式
例：No one can do it. = No one is able to do it.
I’m sorry I haven’t been able to answer your letter.
3.may “可以,许可,” 例：May I borrow your ruler?
may not “也许不” 例：Today Jim may not come to our party.
01.I ______ follow you. Would you please repeat it?
A. can’t
B. mustn’t
C. needn’t
D. shouldn’t
02.—I forgot to bring my dictionary. Could I use yours?—Yes, you ______.
A. can
B. must
C. could
D. should
03..--Pauline has lost her phone. –No. It’s in her bag. I _________ hear it.
A. must
B. can
C. may
D. shall
04.. Finish your homework first, then you’ll _______ watch TV for an hour.
A. can
B. be able to
C. able D could
05.. —_______ I have lunch now, Mom?—No. You must wash your hands first.
A. Would
B. May
C. Ought to
06..— Have you decided where to go for your summer vacation?—Not yet. We _______go to Qingdao .
It's a good place for vacation. A. may B. need C. must
07.. you please give me a hand? The box is too heavy.
A. Should
B. Could
C. Must
D. Need
4.must “必须” 例：You must finish the work today.
must not =mustn’t “不可以，不应该” 例：You mustn’t lend the book to someone else.
★must和have to都表示必须，must强调主观看法，have to强调客观事实需要。

must只有现在和过去两种形式，而have to有更多的时态形式。

例：I must finish the work. （主观上想完成）
My teacher will come to my home, so I have to clean my room. （老师要来是客观原因）
We will have to finish the work. （用于将来时用have to，而must则不能）
5.need “必要,必定” 例：You need start the work now.
needn’t =need not “不必” 例：We needn’t hurry.
★need还用作实意动词，有各种变化
例：He needs to know it. （肯定句）
He doesn’t need to know it. （否定句）
Does he need to know it? （一般疑问句）
6.have to +动词原形，表示“必须做---”。

例：He has to finish his homework at first. He doesn’t have to finish his homework at first.
The boys have to finish their homework at first. The boys don’t have to finish their homework at first.
01.—Dad, must we wait until the light becomes green?—Yes, I'm afraid we______ .That's the traffic
rule.
A. can
B. may
C. have to
D. need
02.—Excuse me, may I keep the book a little longer?—Sorry. You ________ return it today.
A. must
B. mustn’t
C. can
D. can’t
03.Children _______ sit in the fro nt seat of a car. It’s too dangerous.
A. need
B. needn’t
C. must
D. mustn’t
04.We ______ pay to get into the concert. It's free.
A. can’t
B. mustn’t
C. might not
D. don’t have to
7.情态动词的一般疑问句的回答有变化
Can he swim? Yes, he can. No, he can’t.
May I watch TV now? Yes, you may(can). No ,you mustn’t.或can’t.
Must I finish the work now? Yes, you must. No, you needn’t. =you don’t have to.
01.—Must I water the flowers now, mum?—No, you . You do it later.
A. mustn’t; must
B. mustn’t; ma y
C. needn’t; may
D. needn’t; must
02.—May I take this magazine out of the reading room?—No, you ____. You read it in here.
A. mightn’t
B. won’t
C. needn’t
D. mustn’t
03.—Can I park my car in front of the building?—No, you ________.
A. won't
B. can't
C. needn't
D. couldn't
04.—May I play computer games, Mom?—No, you ____________.
A. don’t
B. can’t
C. wouldn’t
D. won’t
05.—May I smoke here? —No, you _______. This is a no-smoking room.
A. needn’t
B. mustn’t
C. couldn’t
D. wouldn’t
8.情态动词表示猜测
情态动词推测意思
①must must + 动词原形“一定是---”
②may \might may\might +动词原形“也许是---”
③could could +动词原形“可能是---”
④can can’t + 动词原形“不可能是---”
例：①You must be ill. I can see it from your face. (一定是病了，表示对现在的推测)
②John is absent. He may\might be ill. (也许是病了，表示对现在的推测)
③The guitar could be Jim’s. (可能是，表示对现在的推测)
④He can’t be in the room. （不可能是，表示对现在的推测）
01.—Who’s singing in the garden?—It be Mr. Brown. He always practices singing at this time.
A. must
B. can’t
C. need
02.—Is the man over there Mr. Brown?—It ______ him. He has gone to Brazil to watch the 2014 FIFA
World Cup.
A. may not
B. can’t be
C. shouldn’t
D. mustn’t
03.—Bob, where is Linda?—She _______ be in the library, bu t I am not sure.
A. must
B. may
C. need
D. has to
04.— Where are you going this month?— We______ go to Xiamen, but we're not sure.
A. needn’t
B. must
C. might
D. mustn't
05.—Is Mr Brown driving here?—I’m not sure. He ______ come by train.
A. may
B. shall
C. need
D. must
9.had better +动词原形，表示“最好做---”。

例：You had better take the books away.
否定句：had better + not + 动词原形。

例：You had better not take the books away.
10.should + 动词原形，表示“应该做---”。

例：They should finish the homework on time.
shouldn’t 表示“不应该---” 例：They should not finish the homework at school.
01.It’s rather hot in the room. You’d better _______ the windows or the door.
A. close
B. not to close
C. don’t close
D. not close
02. A country has dreams. We teenagers ________ also have dreams. With dreams and hard work,
A. may
B. must
C. should
—I know by what time you want the project to be done?—By the day after tomorrow. you finish it on time? A. May; Can B. Must; Need C. Could; Must D. Need; Would
2.—Must I hand in my homework now, Mr. Smith?—No, you _______.A. can’t B. sho uldn’t C. wouldn’t
D. needn’t
3.The man is feeling much better now, so you ______ call a doctor. A. needn’t B. can’t C. mustn’t
D.shouldn’t
4.If you _____ smoke, please go outside. A. can B. may C. must D. might
5.Look at the “No parking” sign. You _____park your c ar here. A. should B. must C. needn’t D. mustn’t
6.—_______ you leave now? You only arrived here an hour ago.—Sorry, but so much homework is waiting for me.
A. May
B. Must
C. Can
D. Might
7.Here is my phone number. You _______ call me anytime you like. A. must B. can C. should D. need
8.—Let’s go climbing, shall we?—You ____ be joking! Don’t you know I’m afraid of high places?
A. may
B. can
C. must
D. should
9.—Are you interested in shopping online?—Not so much. We ____ see real products but pictures.
A. shouldn’t
B. can’t
C. mustn’t
D. needn’t
10.—Could you please have a walk with me?—Sorry, I ____. I have something important to do now.
A. mustn’t
B. needn’t
C. can’t
D. may not
11.—Lingling, can I use your e-dictionary?—Sure. But you _______ return it after class.
A. must
B. can
C. may
D. would
12.—Look, someone left a book.—Oh, yeah… This book _______ be Kitty’s. Only s he likes to read this kind of books.
A. can
B. must
C. may
D. might
13.—Is the long-haired man Bruce?—No, it _______ be him. He’s in New York now.
A. can’t
B. mustn’t
C. needn’t
D. may not
14.People _______ wai t until the traffic becomes green. That’s the traffic rule.
A. must
B. can
C. need
D. may
15.—Li Lei, hurry up! The bus is coming. —Oh, no. We ______ cross the street until the traffic lights turn green.
A. mustn’t
B. may not
C. needn’t
D. have to
16.—How many English words do you think I should know?—As many as you ____. Then you will find reading quite easy.
A. will
B. must
C. can
D. might
17.Excuse me, sir. You ______ open the door before the train stops.
A. mustn't
B. needn’t
C. may not
D. don’t have to
18.You mustn’t go off on your own, because you_______get lost in the mountains.
A. should
B. must
C. need
D. might
19.—Are you in a hurry?—NO, I’ve got plenty of time I wait.
A. can
B. can’t
C. must
D. mustn’t
20.—_________ I help you, sir?—Yes. I want a T-shirt. A. Can B. Should C. Must D. Would
21.—Honey, stay home before I return. —I ________, mum. A. must B. can C. will
D. should
22.—Can I borrow your ruler，please?—Yes，you . But you must return it to me before lunchtime.
A. have
B. can
C. must
D. used to
23.—Difficulties always go with me! —Cheer up! If God closes a door in front of you, there ______ be a window opened for you. A. would B. must D. could D. can
24.Amy, I hear you’ve got many foreign coins. __ I have a look? —Of course, I’ll fetch them for you.
A. May
B. Must
C. Should
D. Need
25.29. —Honey, how are you feeling now?—I am much better, Mum. So you ________ take me to see the doctor.
A. can't
B. mustn't
C. needn't
D. couldn’t
26.Could you please tell me how to improve my spoken English?---Certainly, I_______. A. can B. could C. must
27.( )Excuse me. How can I get to the railway station? ---Turn left and then follow your nose. You _____ miss it!
A. mustn’t
B. can’t
C. shouldn’t
D. needn’t
28.( )May I take my pet dog with me into the cinema? ------The rule says no. So you ________.
A. can
B. mustn’t
C. may
29.( )Will you answer the telephone? It ________ be your mother. ------Sorry, I ________. I’m busy.
A. can, mustn’t
B. will, can’t
C. may, can’t
D. need, will
30.( )Would you please help me with the questions? ---Sorry. You ___ go and ask Mary. She ___ know the answer.
A. must, can
B. can, may
C. need, can
D. must, may
31.( )Let’s go to the concert tonight, Michael! ---Sorry, I _____. I have to help my mother with the housework.
A. mustn’t
B. may not
C. needn’t
D. can’t
32.( )It seems that it is going to rain. You’d better ________ the windows open when you leave the house.
A. not leave
B. leave
C. not to leave
D. to leave
33.( )Four hundred dollars for a pair of shoes! You ________ be joking!
A. may
B. can
C. need
D. must
34.( )There is somebody at the door. ________ I go and see who it is?
A. Shall
B. Must
C. Will
D. Would
35.( )We ________ fight against pollution. A. may B. should C. mustn’t D. needn’t
36.( )Is Simon coming by train? ------He should, but he ________ not. He like s driving his car.
A. may
B. shall
C. need
D. must
37.( )Will you please stay here for the party? ---Sorry, I ________. I’ll have to go to an important meeting.
A. mustn’t
B. needn’t
C. can’t
D. won’t
38.( )________ I have to show the school report to my parents, Miss King! ------Yes, you do.
A. Must
B. Do
C. Can
D. May
39.( )You must come back every month. ------Yes, I ________. A. will B. must C. should
D. can
40.( )Tom, you _______ play with the knife．You______ hurt yourself．B
A. won't; can't
B. mustn't; may
C. shouldn't; must
D. can't; should
41.( )–I’m afraid I need a pair of glasses. I ____ hardly see the words on the blackboard.--- That’s terrible. You may have got poor eyesight. A. can B. must C. may D. need
42.( )Last year I ______ drive. I used to take the bus. A. could B. couldn’t C. should D. shouldn’t
43.( )—______ I try on those shoes in the window?—______. They are just on show.
A. Could; Yes, you can
B. Can; Sorry, you couldn’t
C. Could; Sorry, you can’t
D. Can; Yes, you could
44.( )---Have you heard that some bad thing would happen in 2012?---Don't worry! The news_____ be true.
A. mustn't
B. may not
C. needn't
45.( )Drivers _______wear the safety belt when driving. This is the traffic rule. A. can B. may C. will
D. must.
46.Peter , we need to clean the house. Could you please ( sweep ) the floor?
47.If you don’t tell me what the problem is, I can’t (help) you.
48.We must the teacher’s instructions when we are in the lab.
49.David can very fast. I’m sure he will win the race at the sports meeting.
50.It’s 11:00 in the evening now. You can’t the last bus.
51.You shouldn’t about your mother. She is OK.。