英語情態動詞（can,could,will,would,may,should,shall,must等）：
本身具有一定的詞義，表示說話人的情緒和態度，如可能、需要、意願、肯定或懷疑等。2.但它們的詞義不完整，不能單獨做句子的謂語，後需跟(實義)動詞原形一起構成複合謂語。
3.情態動詞沒有人稱和數的變化(即情態動詞不隨主語的人稱或單複數而變化)。
4.否定形式是直接在情態動詞後加not。如can not; may not; will not 等。
5.一般疑問句是直接把情態動詞提到句首。
一、can的用法。
1.表示能力→「 能、會」
We can speak English. → We can not( can't) speak English .
我們會說英語。 我們不會說英語。
Can you dance the disco? →Yes, I can. / No, I can’t.
你會跳舞嗎？ 是的，我會。不,我不會。
(此時可用be able to代替。Can只有一般現在時和一般過去式；而be able to則有更多的時態.)
We are able to speak English.= We can speak English.我們會說英語。
We were able to speak English at the age of five 我們五歲時就會說英語。
= We could speak English at the age of five. Tom will be able to go traveling abroad.湯姆將會去國外旅行。
2.表示請求或允許→「可以」
Can I borrow your book? →Yes, you can. / No, I’m afraid not.
我可以借用你的書嗎？ 是的，你可以。 不，恐怕不行。
You can sit down. 你可以坐下。
3.表示客觀可能性→「可能、可能會」
I think he can come back soon.我認為他很快會回來。
但在否定句中時，表示一種否定推測「不可能、一定不是」。
He can't be a policeman.他不可能是警察。
My father can't be at home because he is busy working.
我父親一定不在家，因為他在忙著工作。
4.could 是can 的過去式，用於過去時態中。
I can swim now 現在我會遊泳
but I couldn't swim last Summer.但是去年夏天我不會遊泳
She said she could play the piano.她說她會彈鋼琴。
但在一般現在時態中can、could 都可表示請求和允許，但could更委婉客氣,
但回答時仍然用can。
Could you help me with my English? → Yes./No problem/Sure/All right
你可以幫助我複習英語嗎？ 可以的/沒問題/ 當然/ 好的
Could you please come to my office? →Sorry, I’m afraid not(I can't).
你可以來我辦公室嗎？ 抱歉，我恐怕我不能來
Could I see your driving license?→Of course you can
我可以看你的駕駛證嗎？ 當然可以
二、may的用法。
might是may的過去式，might可指過去時間，也可指現在時間，指現在時間時，語氣更委婉客氣。
1、表示請求或允許→ 「可以」
You may(might）use my English book.你可以用我的英語書。
May (Might) I smoke in this room? 我可以在這個房間抽菸嗎？
→Yes,you may/you can/Sure/Of course.可以/當然可以
→No,you can't/you may not/you mustn't.不可以/不允許
特別的是否定回答，表示「不可以，禁止」意思時，常用must not (mustn’t)。
May I smoke in this room? 我可以在這個房間抽菸嗎？
→No, you mustn’t. It is harmful to others』 health.
不，不允許。 吸菸對別人身體有害。
用May I...？徵徇對方許可時比較正式和客氣，而用Can I...？在口語中更常見。
2、 表推測，屬於沒把握的推測，可能性很小→ 「可能、也許」。
He may( might) be my English teacher.他也許是我的英語老師。
I may(might) go fishing tomorrow.我明天也許去釣魚。
備註：1）might不是指過去時間，它所表示的可能性比may小。
2）Can/May/Could/Might I.....?表示請求對方許可。其中can語氣最不正式could語氣比較客氣委婉；may/might用於正式場合，語氣客氣恭維；might比may更為客氣。
三、must的用法。
1、表示義務、職責、勸告或主觀意識上→「必須，一定」
We must obey the traffic rules.我們必須遵守交通規則。
Everyone must have healthy eating habits。每個人一定要有健康的飲食習慣。
You must get to school on time. 你必須要準時到校。
Must she get there at 6 o'clock? 她必須六點到那嗎？
（1）must的否定形式must not(mustn't) 表示「禁止、不允許、不可以」，語氣強，多為法律、規章等所禁止。
You must not break the law in our country.在我們國家，禁止違反法律。
You must not park the car here.這裡禁止停車。
（2）Must開頭問句的回答：
否定回答不能用mustn’t,而用needn’t, don’t have to（不必要）.
Must I get there at 6 o'clock? 我必須六點到那嗎？
→Yes, you must.是的，必須。
→No,youneedn’t 或者No, you don’t have to.不，不必要。
2、表示推測，屬於有把握、肯定的推測，「準是、肯定、一定」，只用於肯定句中。
(1)must +動詞原形 → 「準是/肯定........」，表示對現在情況的推測。
She must be our new English teacher.她準是我們的新來的英語老師。
There must be something wrong with my computer because it doesn't work.
我的電腦準是有問題，因為沒法運行了。
(2)must + have + done(動詞過去分詞)
→「準是/肯定已經做了某事」，表示對過去發生事情的肯定推測。
There is nobody here--they must have gone home.
這兒沒人 ---他們準是已經回家了。
若是否定推測，則用can not (can't)，「不可能、一定不是」
He can't be a policeman.他不可能是警察。
My father can't be at home because he is busy working.
我父親一定不在家，因為他在忙著工作。
3、must 與 have to(has to) 的區別
( 1)must通常表示由於責任、義務等主觀原因而「必須」要做某事：
We must obey the traffic rules.我們必須遵守交通規則。
We all must take good care of our elder parents.
我們都必須照顧好我們年邁的父母。
(2)have to 表示由於客觀原因而「不得不、必須」做某事，有迫不得已之
意，可用於多種時態：
My parents aren't in,
I have to stay at home to look after my young sister.
父母不在家，我不得不在家照顧妹妹。
She had to go to school by bus yesterday because her bike was broken.
昨天自行車壞了，她不得不乘公交上學。
四、shall 的用法。
有「將會、將要」的意思，可用於表將來，主語常常是第一人稱。
We shall read some more books.我們要再買些書。
但主要用於第一人稱的疑問句中,表示徵求對方意願，
When shall we meet? 我們什麼時候見面？
Shall we go to visit our teacher? 我們去拜訪老師好嗎？
五、should 的用法。
1、 表示義務、建議、勸告→「應該、應當」做某事，
We should listen to the teacher carefully in class.課堂上我們應該認真聽講。
It is cold outside, so you should put on the warm coat.
外面很冷，你應當穿上保暖外套。
We should not（shouldn't) laugh at the disabled people.
我們不應該嘲笑殘疾人。
六、will的用法。 → would 是will的過去式。
1、will用於表一般將來時，有「將會、將要.」之意。
I am sure I will(I』ll)do better next time. 我確信下次我將會做得更好。
We will(We』ll)take some sports clothes and sports shoes tomorrow.
明天我們將會攜帶些運動服和運動鞋。
We will not (won't)help him if he asks us.如果他問我們，我們不會幫助他。
2、will表示意願 或徵詢意見，有「願意.」之意，常用於疑問句中，但would用於現在時間，比will語氣更委婉、客氣。
Will you go to the party with me? Will you mail the letter for me,please?
你願意和我去參加宴會嗎？ 你願意給我寄封信嗎？
Would you please give me a hand ?你願意幫忙嗎？
Would you like some more milk?→Yes, please →No, thanks.
你想要再來點牛奶嗎？
What would you like to have for breakfast?你早餐想要吃點什麼？
→I would（'d）like to have some milk and bread for breakfast.
Would you like to go shopping with me? 你想和我去購物嗎？
→Yes/I』d like to./Sure, I'd love to / I』d like to/ Good idea
/ Sorry,I’m afraid not
Would you mind passing me some water? 你介意遞給我些水嗎？
→No,of course not/Certainly not/Not at all
→Sorry,but.../I’m afraid not(I can't)
3.would 用於過去將來時態，表示從過去某一時刻看以後要發生的動作或狀態。
At that time they said that they would help me.當時他們說他們會幫助我。
He told her that he would meet her at the coffee shop after work.
他告訴她，她將會在下班後在咖啡店見她。
七、need的用法。→有「需要」之意。
1、need作情態動詞，表示必要性， 多用於否定句和疑問句中。
You need not( needn't) come back home.你不需要回家。
Need I say it once again? →Yes, you must →No,you needn't.
2、need做實義動詞時，後可接名詞、代詞或帶to的不定式做賓語：
→ need sth.需要某事/某物 ； need to do sth.需要做某事。
We need many friends. → We don’t need many friends.
→Do you need many friends?→Yes,we do.→No,we don't.
She needs to go to school on foot.她需要步行去上學。
→Does she need to go to school on foot?
→Yes,she does.→No,she doesn't.
八、dare的用法。 →有「敢」之意。
1、dare作情態動詞 ，多用於否定句和疑問句中。
I dare not speak English in public.我不敢在公眾場合說英語。
Dare you speak English in public? Yes,I dare;No, I dare not
How dare you speak to me like that. 你怎麼敢這樣對我說話。
2、做實義動詞時，後可接名詞、代詞或不定式做賓語
dare (to)do sth. 敢做某事
She dares to go out alone at night.晚上她敢獨自一人出去。
Tom dared to come to school late yesterday. 湯姆昨天竟敢上學遲到。
I don't dare to speak English in public. 我不敢在公眾場合說英語。
Do you dare to speak English in public? Yes,I do;No, I don’t
練習。
You _______ eat too much candy. It’s bad for your teeth.A.must B.can C.should D.shouldn’t
2.If you have a headache, you _______ lie down for a good rest.
A.shouldn’t B.had better not C.had better D.mustn’t
3.—I can’t keep myself active during the day.
—You _______ take more exercise.
A.must not B.must be C.need to D.may be
4. You _______ walk across the road. It’s dangerous.
A.may not B.don’t have to C.must not D.needn’t
5.—May I ask you some questions, Dr. Wang?
—_______
A.You’re welcome B.Sure, go ahead. C.No, I’m busy. D.Yes, you must.
6.—Must I take part in the activity?
—No, you _______. You’re too young. You should look after yourself.
A.mustn’t B.don’t C.can’t D.don’t have to
7.—Must I take the medicine every day?—No, you _______.
A.must B.mustn’t C.needn’t D.can’t
8.My mother is ill. I _______ stay at home to take care of her.
A.can B.may C.should D.maybe
9.—May I use your dictionary, Lily?—Sure, _______.
A.go ahead B.you can ask Bill C.you can’t D.that’s all right
10.You』d better _______ too much meat. You are much too fat.
A.not eat B.eat C.not to eat D.don’t eat
11.You _______ wash your hands before meals. It is good for your health.
A.may B.can C.have to D.must
12.Don’t sleep all day. You should _______ to keep fit.
A.not eat B.to run C.do many exercise D.do morning exercises
13.—Would you please _______ so much noise?
—Oh, sorry, I won’t.
A. not make B.don’t make C. not to make D.making
14.—Must I park my car behind the building?
—No, you _______. You _______ park it there.
A.mustn’t; may B.may not; must
C.don’t have to; may D.shouldn’t; must
15.We _______ play on this road. There is too much traffic.
A.must B.mustn’t C.need D.needn’t
16.Everyone _____ the traffic _____.
A.should listen; rules B.will do; rules
C.must obey; rules D.must obeys; rule
17.—Do I need _____ a bus?
—Yes, No.3 bus will take you there.
A.taking B.to take C.takes D.to taking
18.— _____ Alice perform ballet two years ago?
—No, she _____ . But now she _____ .
A.Can; can’t; could B.Could; can; can
C.Could; couldn’t; could D.Could; couldn’t; can
19.—Can Bill _____ the party?
—Of course, he can.
A.comes B.come C.comes to D.come to
20.—Could you ride a bike when you were 5 years old?
—_____
A.Yes, I could. B.Yes, I couldn’t. C.Yes, I can. D.No, I can’t.
21.----May I swim in this river?
No,you____ .It is dangerous.
A. won't. B. needn't. C. mustn't. D. may not.
22.----You see,a man is cutting a tree on the moon.
----It _____ be true. The teacher says there is no air on the moon.
A. can't. B. shouldn't. C. mustn't. D. may not.
23.----Look!The man at the gate_____be our headmaster.He is always standing there every morning.
No,it____be him.He is holding a meeting in the office now.
A. must;can't. B. must;mustn't.
C. can't;can't. D. can't; mustn't.
24.SARS is a serious disease,but we_____be afraid of it.
A. must B. may C. had better D. don't need to
25.----You____smoke in the meeting room.
I'm sorry.
A. had better not B. didn't had better
C. don't had better D. hadn't better
26.Will you finish your work before nine o'clock this evening?
A. can B. may C. are able to D. be able to
27.Whose notebook is this?
-It___Jane's.It has her name on it.
A. must be B. may be. C. could be. D. might belong to.
28._____I borrow these magazines?
Sorry,only the magazines over there can be borrowed.
A. Must B. May C. Would D. Need .
29.----Where is Mum now?
I'm not sure.She____be in the kitchen.
A. shall. B. may . C. must. D. need.