高中情態(tài)動(dòng)詞的重難點(diǎn)突破
2011年11月02日 08:34
來源：本站原創(chuàng)
高中情態(tài)動(dòng)詞的重難點(diǎn)突破
一.概念:
情態(tài)動(dòng)詞是表示能力,義務(wù),必須,猜測等說話人的語氣或情態(tài)的動(dòng)詞.
二.相關(guān)知識點(diǎn)精講:
1．can
1)表能力
He is only four , but he can read.
Fire can’t destroy gold.
2)表可能性
Can the news be true?
It can’t be true.
What can he possibly mean?
Attending the ball can be very exciting.
3)表示允許
Can (May) I come in ?
Can I smoke here ?
4)有時(shí)會(huì)
Training alone can be dangerous.
2.could的用法
1)表過去的可能和許可，
Father said I could swim in the river.
2)表過去的能力
I could swim when I was only six.
He could be very naughty when he was a child.
3)表“允許”?？杀硎疚窨蜌獾奶岢鰡栴}或陳述看法
Could I use your bike?
Yes, you can.
4)Could/can+have done 結(jié)構(gòu)表示對過去發(fā)生的事情的“懷疑”或“不肯定”。 could 加完成式還用于肯定句時(shí)一般表過去本可以完成卻未完成的動(dòng)作（虛擬）。
Can they have won the basketball match？
You could have completed the task a little earlier.
I could have passed my examination easily but I made too many stupid mistakes.
3.may 的用法
1)表示請求、可以、允許。
You may drive the tractor.
2)當(dāng)回答由may 引起的問題時(shí)，否定答語要用must not,表示“不許可”、“不應(yīng)該”、“不行”。
May I come in?
Yes, you may.
No,you can’t
No, you may not .
No ,you mustn’t
No ,you’d better not.
3) may /might 推測性用法 可能
He may be right.
He may not come today
He may /might come tomorrow.
注意 : (1)只用于肯定和否定句中,不用于疑問句中。
(2) might 比may可能性更小
He might get a job.
He may get a job.
(3) may not 可能不 can not不可能
He may not come
He can’t come
3)表建議（可和as well 連用）
You may（might）as well stay where you are.（may as well “還是……的好,不妨”
4)表祝愿
May you be happy!
might
1)表過去的“可能”和“允許”多用于間接引語。
She said that he might take her dictionary.
2)表現(xiàn)在的“可能”，其可能性要比may小。
Electric irons could be dangerous; they might give you a severe shock.
3)may (might) + have +done 表示對過去發(fā)生行為的推測，含有“想必”、“也許是”的意思；也許會(huì)做了某事但沒做到（虛擬）
It may have been true.
He might not have settled the question.
4.must 的主要用法。
1)表示必須、必要
We must do everything step by step .
Why must you always bother me?
2)must be + 表語的結(jié)構(gòu)，通常表示猜測，含有“一定”之意。（只用在肯定句中）
He must be an honest boy.
This must be your room.
3)must 的否定式有兩個(gè)：當(dāng)回答由must引起的問題時(shí)，否定答復(fù)要用needn’t或don’t have to 表示“不必”、“無須”、“用不著”、“不一定”的意義。當(dāng)表示“不應(yīng)該”、“不許可”、“禁止”時(shí)，就用must not。
Must I go tomorrow?
Yes, please.
No , you needn’t.
4)must +have +過去分詞的結(jié)構(gòu)，常用在肯定句中，表示對過去發(fā)生行為的推測，含有“一定”、“準(zhǔn)是”的意思。否定和疑問句用can。
She must have studied English before.
5.have to的含義與must是很接近的,只是have to 比較強(qiáng)調(diào)客觀需要，must著重說明主觀看法。
I must clean the room.（主觀想法）
I have to clean the room.（客觀需要）
另外，have to 能用于更多時(shí)態(tài)：
We had to be there at ten .
We will have to reconsider the whole thing.
have to 的否定式：don’t have to do 表示“不必做……”之意。
6.ought to 的用法
Ought to 用于否定句，其否定形式可縮略為oughtn’t ，如：
You oughtn’t to smoke so much.
也可以用于疑問句，如：
Ought you to smoke so much?
7.shall的用法
1)用于第一人稱征求對方的意見，如：
What shall I wear on the journey?
Shall we dance?
2)shall 用于第二、三人稱時(shí)表允諾，警告，命令，威脅（現(xiàn)已少見），如：
She shall get her share.
You shall have it back tomorrow.
情態(tài)動(dòng)詞should一般不應(yīng)被認(rèn)為是情態(tài)動(dòng)詞shall的過去式，
3)“should+be+表語”的結(jié)構(gòu)，表示推測或驚奇。例如：
They should be back by now.
I am sorry that she should be so careless.
4)“should+have+過去分詞”的結(jié)構(gòu)，表示過去該做而實(shí)際上尚未做的動(dòng)作或行為；其否定則表示發(fā)生了不應(yīng)該發(fā)生的行為。其同義結(jié)構(gòu)“ought to have +過去分詞”,表示過去“早應(yīng)該”、“本當(dāng)”之意，語氣較強(qiáng)。例如：
I should have thought of that.
They should not have left so soon.
5) 在“It is natural (strange, natural, necessary, surprised, impossible, important ) that……”句型中，主語從句中的謂語動(dòng)詞要用should +動(dòng)詞原形”表示“理所當(dāng)然”、“奇怪”、“必要”、“驚異”等的意思。在lest（以免）、for fear (that) (以防)、in case（以備萬一）等之后也要用should+動(dòng)詞原形;在advise, sugest, order, demand, request 等的從句中should+do”例如：
It is necessary that he(should) be sent there at once.
It is strange that he should say so.
Let us go at once lest we should be late for the train.
8..will和would的用法
1）表示意志，決心或愿望。例如：
Surely we will support all the people in the world in their struggle for peace.
He would not let me try it .
2）用于第二人稱作主語的疑問句中，表示對對方的請求，would的語氣比will委碗
Would/will you kindly tell me the way to the station?
4）表可能性
This will be the book you are looking for.
She would be about 60 when she died.
9. need和dare的用法
情態(tài)動(dòng)詞need 實(shí)義動(dòng)詞 need
You need (not) do You (don’t) need to do
He need (not) do He needs (doesn’t need) to do
You needed (didn’t need) to do He needed (didn’t need) to do
You need (not) do You will (not) need to do
He need (not) do He will (not) need to do
句型 時(shí)態(tài) 動(dòng)詞
情態(tài)動(dòng)詞dare 實(shí)義動(dòng)詞 dare
肯定句 現(xiàn)在時(shí) dare to 少用 dare/dares to do
過去時(shí) dare to 少用 dared to do
否定句 現(xiàn)在時(shí) daren’t/dare not do do/does not dare (to) do
過去時(shí) dared not do did not dare (to) do
疑問句 現(xiàn)在時(shí) Dare he do? Do you/Does he dear (to) do?
過去時(shí) Dared he do? Did he dare (to) do
needn’t have v-ed 表示過去做了某事，但沒有做的必要，意為“本沒必要…”。例如：
You needn’t have waken me up; I don’t have to go to work today
10.表推測的情態(tài)動(dòng)詞句子的反意疑問句
He must/may be in the room, isn’t he?
He can’t be in the room, is he？
He must have finished the work, hasn’t he?
He may have done the work last night, didn’t he?
：情態(tài)動(dòng)詞+行為動(dòng)詞進(jìn)行式
情態(tài)動(dòng)詞+行為動(dòng)詞進(jìn)行式（即情態(tài)動(dòng)詞+ be + v-ing形式），表示推測或評論某動(dòng)作現(xiàn)在是否正在進(jìn)行。例如：
1）He must be playing basketball in the room.
2）She may be staying at home.
11.情態(tài)動(dòng)詞+行為動(dòng)詞完成進(jìn)行式
情態(tài)動(dòng)詞+行為動(dòng)詞完成進(jìn)行式（即情態(tài)動(dòng)詞+ have been + v-ing 形式），表示推測或評論過去某動(dòng)作是否正在進(jìn)行或一直在進(jìn)行。例如：
1）They should have been meeting to discuss the problem.
2）He may / might have been buying stamps in the post office when you saw him.
13．用作情態(tài)動(dòng)詞的其他短語
would rather, would sooner, would (just) as soon, had rather, had better, had sooner, can not but, may (just) as well等可用作情態(tài)動(dòng)詞。例如：
1）The soldier would sooner die than surrender.
2）The brave soldier would as soon die as yield to such an enemy.
3）I’d rather walk than take a bus.
4）If you don’t like to swim, you may just as well stay at home.
注：這些短語后一般直接跟動(dòng)詞原形.would (had) rather, would (had) sooner, would (just) as soon后可跟that 引導(dǎo)的從句，that 常省去，從句要用虛擬語氣。對現(xiàn)在和將來的假設(shè)用過去時(shí)，對過去的假設(shè)用過去完成時(shí)。例如：
1）I would rather you came on Sunday.
2）I would sooner you hadn’t asked me to speak yesterday.
三. 鞏固練習(xí):
1. _____ you ready?
(A) Are (B) Have (C) Will (D) Can
2. ____ here early?
(A) Will he (B) Was he (C) Did he be (D) Were he
3. I ___ happy about the price of eggs.
(A) am't (B) am not (C) do not (D) won’t
4. Since last year I____ him only once.
(A) have seen (B) have been seeing (C) see (D) was seeing
5. Donald ___ sixteen tomorrow.
(A) is being (B) going to be (C) shall be (D) will be
6. I ___ the story at all.
(A) don't like (B) like (C) am fond of (D) would like
7. I would rather ___ than play now.
(A) to study (B)am studying (C) study (D) studied
8. I'd rather you ___ anything about it for the time being.
(A) do (B) didn't do (C) don't (D) didn't
9. The car___much money.
(A) not cost (B) not have cost (C) isn't cost (D) didn't cost
10. I ___ like to eat fish.
(A) am (B) have (C) do (D) be
11. ___ repeat the question?
(A) Shall I (B) Will I (C)Would you like that I (D) Do you want that I
12. My teacher knows more than ___.
(A) my uncle knows (B) my uncle does
(C) they know (D)they don't know
13. He___to meet us at the station, but didn't see us.
(A) did go (B) did went (C) goes (D) had
14. Not only ____us light.
(A) does the sun give (B) the sun gives
(C) gives the sun (D) the sun does give
15. ____ you tell me what has happened?
(A) May (B) Must (C) Can (D) Could
16. Anne___tomorrow.
(A) can sing (B) can to sing (C) is going sing (D) going to sing
17. You___hand it in at once, you may hand it in tomorrow.
(A) needn't (B) may not (C) can't (D) must not
18. Tell the boy that he ___ in the river.
(A) swims (B) swim (C) swimming (D) to swim
19. Joan___play on Saturday.
(A) going to (B) can (C) is going (D) can to
20. Susan and I can go to the lecture ___.
(A) but neither can Charles (B) and so Charies can
(C) but Charles can't (D) and Charles also can
四.答案
1. (A) 2, (B) 3. (B) 4. (A) 5, (D) 6, (A) 7. (C) 8. (B) 9. (9) 10, (C)
11. (A) 12. (B) 13. (A) 14. (A) 15. (D) 16. (A) 17. (A) 18. (B) 19. (B) 20, (C)
