高考英語語法精品講練：第四章情態動詞
高中英語語法精講第四章情態動詞.
情態動詞表示說話人對動作或狀態的各種觀點和態度，如需要、猜測、意愿或懷疑等。情態動詞有詞義，但不完全，是所謂的“輔助性”動詞，在句中不能單獨充當謂語。情態動詞的特征和形式 A.情態動詞的各種形式見下表： 情態動詞 may might can could must have to ought to will would shall should need dare used to否定式 may not might not cannotcan not could not must not do not have to ought not to will not would not shall not should not need not dare not used not to did not use to
簡略否定式 mayn't（老式英語，現在不常見） mightn't can't couldn't mustn't don't have to oughtn't to（否定句中to可省略） won't wouldn't shan't（只用于英國英語） shouldn't needn't daren't usedn't to didn't use to B．情態動詞除ought to, used to等外，后面只接不帶to的不定式。 1．情態動詞+do You shouldn't be so careless.
你不該這樣粗心大意。 Jessica told him yesterday she might not go on the trip.杰西卡昨天告訴他，她可能不去旅行了。 Difficulties can and must be overcome.困難能夠而且必須克服。 2．情態動詞+be doing She must be listening to pop music.她肯定在聽流行音樂。 You should be reviewing your lessons.你應該在復習功課。 My mother maymight be cooking now.
我媽媽可能正在做飯。 3．情態動詞+have done They might have visited the Great Wall.他們可能參觀過長城了。 He must have got up very early to catch the train.他一定起得很早去趕火車了。 You ought to have come earlier.你本該早一點兒來。 4．情態動詞+be done This word can also be used as a verb.這個詞也可以用作動詞。 Something must be done to stop pollution.必須采取措施來制止污染。 The work ought to have been finished long ago.這工作早就該完成了。C.情態動詞第三人稱單數一般現在時沒有詞形變化。 You ought to wear a raincoat.你應該穿件雨衣。 She ought to wear a raincoat.她應該穿件雨衣。 Plants must have oxygen in order to live.為了存活植物必須有氧氣。 A plant must have oxygen in order to live.為了存活植物必須有氧氣。 D.情態動詞的時態并不是區分時間的主要標志。在一些場合中，情態動詞的現在式和過去式都可以表示現在時間、過去時間或將來時間。 I'm afraid it might rain tonight.我看今晚可能要下雨。 Could I borrow your thermos我可以借用你的暖水瓶嗎？ It's a nice day today. We could go for a walk.今天天氣不錯，我們可以出去散散步。 E.情態動詞是互相排斥的，一般不允許兩個意義相近的情態動詞連用。 【誤】Soldiers must have to obey orders. 【正】Soldiers have to obey orders.
軍人必須服從命令。 【正】Soldiers must obey orders.
軍人必須服從命令。 【誤】Can I be able to borrow two books at a time 【正】Can I borrow two books at a time
我能一次借兩本書嗎？ 【正】Will I be able to borrow two books at a time
我能一次借兩本書嗎？
一、
情態動詞的意義和用法 A. may和might 1．表示請求、許可，常譯為“可以”。在口語中可用can, could代替may，但在正式場合用may。表示允許時，也可用might代替，might不表示過去時，而是表示口氣比較婉轉。 You may take this seat if you like.如果你喜歡可以坐這個位置。 MayCan Could Might I have a talk with you
我可以和你談談嗎？ --- MayMight I come into the room to see my mother
我可以進房間看我母親嗎？ --- No, you mustn't. She needs to have a good rest.不，你不能進。她需要好好休息。 提示： May I ...問句常見的肯定回答和否定回答。 肯定回答 Yes, please. Certainly. Yes, of course. Sure. Go ahead, please.否定回答 No, you can't.（最常見） No, you mustn't.（具有強烈禁止的意思） Please don't. You'd better not. I don't think you can. I'm sorry it's not allowed. 2．表示推測，可譯為“可能，也許”。
Your math teacher maymight be in his office.
你們的數學老師可能在辦公室里。（一般情況下，might表示的可能性很小）
The light isn't on. It maymight be broken.
那盞燈沒有亮，它可能壞了。
There may might be some ink left in the bottle.
瓶子里也許還剩點兒墨水。
注意：
用may表示推測一般不用于疑問句，在疑問句中通常用can來代替。
Can he be at home
他可能在家嗎？
--- Can it be true
這可能是真的嗎？
--- It may be, or may not be.
可能是，也可能不是。
3．用在目的狀語從句中，構成謂語。
He wants to take a taxi so that he may get there in time.
他想坐出租車，這樣他就能及時到達那里。
I arrived at the airport earlier in order that I might meet him.
我早早地就到了機場為了能接到他。
4．有時可以用于祈使句表示祝愿。
May you succeed.
祝你成功
May you be happy.
祝你快樂。
May that day come soon. 希望這一天早日到來。 B. can和could
1．表示能力，可譯為“能，會”。
I can swim.我會游泳。
Emily can dance well and her mother could dance well when she was young.
艾米麗舞跳得很好，她媽媽年輕時舞跳得也很好。
The cinema can seat 1,000 people.
這電影院能容納1，000人。
I could not read such an easy book when I was 7 years old.
我七歲時連如此簡單的書我也看不懂。
2．表示允許、許可，常用在口語中。could比can語氣上要客氣。
--- Could I use your dictionary
我可以用一下你的字典嗎？
---Yes, go ahead.
可以，用吧。（或Yes, you can.但不能說Yes, you could.）
Could Can you tell me how to get to the zoo
勞駕，你能告訴我怎么去動物園嗎？
He asked me whether he could take the book out of the reading room.
他問我可不可以把書帶出閱覽室。
3．表示推測，可用于肯定句（can罕見）、否定句和疑問句，但更常見于疑問句或否定句。在此種用法中can和could沒有時態的區別，只是表示可能性的大小，can表示推測的可能性比could大。
Can he be ill at home
他會是生病在家嗎？
Can the story be true
這個故事會是真的嗎？
He cannot be at home.
他不可能在家。
You mustn't smoke while you are walking around in the woods. You could start a fire.
在林子里走時一定不要吸煙，那樣可能會引起火災。
4．表示驚異、懷疑、不相信等態度，主要用于否定句和疑問句中。
How can you be so careless
你怎么這么粗心？
Where can could they have gone
他們會去了哪里？
He can'tcouldn't be over sixty.
他不可能超過60歲。
5．Could可以用在虛擬條件句中。
If I could fly, I should be very happy.
如果我能飛，我會很高興。
If you had followed my advice, you could have finished it.
如果你當時聽我的，你早就做完了。
If you had tried harder, you could have passed your exam.
如果你再努力些，你就能通過考試了。
６．can與be able to的區別
can表示“能力”時，和be able to相當，許多場合都可以互相替換。但當敘述過去經過一番努力才能完成的事情或前面有特殊說明，表示你有能力時，只能用be able to。 【正】Can you speak any foreign languages
你會說外語嗎？ 【正】Are you able to speak any foreign languages
你會說外語嗎？ 【誤】The fire spread the building quickly but everybody could escape. 【正】The fire spread the building quickly but everybody was able to escape.
大火迅速蔓延到整幢大樓，但大家都逃了出來。 【正】The fire spread the building quickly but everybody managed to escape. 大火迅速蔓延到整幢大樓，但大家都想法逃了出來。
be able to比can有更多形式。
No one could answer the question.
沒人能回答這個問題。（這里could可用was able to代替）
When he grows up, he will be able to support his family.
他長大后就能養家了。
Frank is ill. He hasn't been able to go to school for one week.
弗蘭克病了，已經一周沒去上學了。
I'm sorry for not being able to help you in time.
對不起，不能及時幫你的忙。
could經常和動詞see, hear, smell, taste, feel, remember, understand等連用。
When we went into the house, we could smell something burning.
當我們走進屋子時，我們聞到什么東西燒焦了。（不用was able to）
She spoke in a very low voice, but I could understand what she said.
雖然她講話的聲音很低，但我還是明白了她說的話。
在談論說話時發生的動作，用can，不用be able to。
【誤】Look! I'm able to swim.
【正】Look! I can swim.
看，我會游泳了！ C．must和have to
1．must表示有做某一動作的必要或義務，強調主觀看法，可譯為“必須，應該”。
Everyone must obey the rule.
人人都必須遵守制度。
We must do everything step by step.
我們必須逐步做每件事。
Teachers must be patient enough with their students.
老師必須對學生有足夠的耐心。
2．have to表示因客觀需要促使主語不得不做某事。
You can't turn right here. You have to turn left.
你不能在這里右拐，你必須左拐。
My eyesight is very poor. I have to wear glasses for reading.
我的視力很差，看書時不得不戴眼鏡。
You have to pass a test before you can get a driving licence.
你在取得駕照之前必須先通過考試。
提示：
在口語中，我們可以使用have got to來代替have to.
I've got to work on Sunday.
我不得不星期天工作。
When has Ann got to go 安必須什么時候走？
3．must與have to的比較。
must與have to在表示“必須”這個意思時意義相近，但在用法上有所區別。
must含有說話者的強烈決意（表示主觀的看法），have to則表示外力環境或習慣使然（即表示客觀的必要，作“不得不”解）。
I must study hard.
我必須努力學習。（發自內心的決定）
I have to study hard.
我不得不努力學習。（外界因素逼迫）
You must stay for supper.
你必須留下來吃晚飯。（because I want you to）
You have to stay for supper.
你得留下來吃晚飯。（because there is nowhere else to go）
must只有一種形式，而have to可有多種時態。
They had to put off the sports meet due to the bad weather.
由于壞天氣，他們不得不推遲運動會。
These last two days he has had to take a rest at home.
這兩天他必須一直在家休息。
must的否定式和have to的否定式的意思完全不同。
You must keep it a secret. You mustn't tell anyone.
你必須保密，你不可以告訴任何人。（mustn't表示“禁止”）
You don't have to tell me the secret.你不必告訴我這個秘密。 （don't have to意思是“沒有必要”= don't need to）
4．must用于表示推測，它的肯定程度比may, might, could大得多，一般只用于肯定句。
must do (這里的do通常是狀態動詞或系動詞)，表示對現在狀態的推測。
He must be very lazy for his desk is very untidy.
他肯定很懶，因為他的課桌很不整潔。
Carol must get very bored with her job. She does the same thing every day.
卡羅爾肯定對她的工作厭煩了，她每天都做同樣的事。
must be doing表示對現在動作或狀態的推測。
Put on more clothes. You must be feeling cold with only a shirt on.
多穿點兒衣服，你只穿一件襯衣，肯定覺得冷。
must have done表示對過去的動作或狀態的推測。
The ground is wet. It must have rained last night.
地面是濕的，昨晚肯定下雨了。
I didn't hear the phone. I must have been asleep.
我沒聽見電話鈴響，我一定是睡著了。
提示：
must表示推測只用于肯定句，否定句和疑問句要用can, could來代替must。
He's just had his lunch. He can't be hungry already.
他剛吃過午飯，不會餓的。
They have just arrived here. They can't know many people.
他們剛到這里，不可能認識很多人。
Leslie walked past me without speaking. He can'tcouldn't have seen me.
萊斯利從我身邊走過而沒打招呼，他肯定沒看見我。
5．must可用來表示根據邏輯推理必然要發生的事，可譯為“必然會，總是會”。
We all must die.
我們都會死。
Truth must be out.
真相必然會大白的。
Winter must be followed by spring.
冬天到了，春天還會遠嗎？
6．must有時可用來表示“偏偏”的意思。
Why must it rain today 為什么偏偏在今天下雨？
When I was taking a nap, a student must knock at the door.
正當我午睡時，偏偏一個學生在這個時候來敲門。 D．will和would
1.will和would可用于第二人稱疑問句，表示請求和建議等。would比will委婉客氣。
Will you have some tea
你喝點茶，好嗎？
Will you share your happiness with us
你可以把你的歡樂與我們共享嗎？
Would you pass this book to the student in the last row
請你把這本書傳給最后一排的學生好嗎？ 必背：
WillWould you ...表示請求和建議的答復。肯定回答 Yes, please.是的，請。 Certainly.當然可以。 Sure.當然了。 All right.好啊！否定回答 I'm sorry. I can't.對不起，不行。 No, thank you.不，不行。 No, I won't.不，不行。 2．will和would可表示意志、愿望和決心，用于各種人稱陳述句。 I will do anything for you.我愿為你做任何事。 I will never tell you the secret.我永遠不會告訴你這個秘密。 None is so blind as those who won't see.不愿看的人眼睛最瞎。 They would not let him in because he was poorly dressed.他們不讓他進去因為他衣著破舊。 3．will和would可表示某種傾向或習慣性動作。will表示現在的習慣動作，would表示過去的習慣動作。 He will surf the Internet every night.他每天晚上都在上網。 The boy will sit there hour after hour looking at the traffic go by. 那男孩常常坐在那兒好幾個鐘頭，看著車輛行人通過。 He would be nervous when he met strangers.遇見陌生人時他總是很緊張。 In class he would ask some silly questions, and his classmates would laugh at him.課上，他總是問一些蠢問題，他的同學們總是嘲笑他。 4．will可表示固執堅持，這時will不可使用'll的簡略形式。用于非人稱主語時，表示物體的固有性質和傾向。 I will take the job, and no one can stop me.我就要這個工作，沒有人可阻止我。 He won't do what he's told.他就是不愿按所吩咐的去做。 The window won't open.窗子打不開。 This glass will not crack under heavy pressure.這種玻璃在重壓下也不會破碎。
5．will表示將來時間時，不可用于條件狀語從句，但will表示意愿或決心時，可用于條件狀語從句。
If you will read the book, I'll lend it to you.
如果你愿意讀這本書，我會把它借給你。
If you will give up smoking, your health will improve. 如果你愿意把煙戒掉的話，你的健康狀況就會好轉。
6．will和would可表示推論或猜測。
The patient took the sleeping pills an hour ago. He will be asleep now.
病人一小時前吃的安眠藥，現在應該睡著了。
It would be about ten when he left home.
他大約在十點鐘離開的家。
I thought he would have told you about it.
我認為他已告知你此事。
It would be raining when she went home.
她回家時可能正在下雨。 比較：
Would you like ...表示邀請
Do you like ...表示習慣
——Do you like going go the cinema
你喜歡看電影嗎？
——Yes,I go to the cinema a lot.
是的，我經常去看電影。
——Would you like to go to the cinema tonight
今天晚上去看電影好嗎？
——Yes, I'd love to.
非常樂意。
