姜堰中学高考英语情态动词.doc

情态动词和虚拟语气讲解(七)
何春喜校欣梓
一、情态动词
(一)情态动词的基本用法
1. can/could
(1)表“能力”。
Just be patient. You can’t expect the world to change so soon.
We couldn’t eat in a restaurant because none of us had any money on us.
(2)表“许可”。回答could的提问常用can,一般不用could。
---Could I use your bike?
---Yes, surely you can .
(3)could一般只表示过去的能力;若表示过去的能力得到了实施,一般用was/were able to,不用could。
The fire spread throughout the hotel very quickly but everyone was able to get out.
2. may/might
(1)表“许可”(=can)。若表示“不可以、禁止”,用mustn’t或can’t。回答might的提问常用may,一般不用might。
A: --- May I take the book out?
B: ---I’m afraid not.
A: ---Might I use your pen?
B: ---Yes, of course you may .
A: ---May I watch TV now?
B: ---No, you mustn’t .
(2)may表“祝愿”,置句首,主谓要倒装。
Good luck to you, and may all your e true!
3. must/have to
(1)表“必需”。must强调主观看法;have to强调客观需要。
This is a bad party---We really must go.
This is a lovely party, but we have to go because of our baby.
(2)mustn’t意为“禁止、不准”;haven’t to意为“不必”(=needn’t)。
You mustn’t practice the drums while the baby is sleeping.
(3)must表“偏要、硬要”。
Why must you always interrupt me?
A: ---May I smoke here?
B: ---If you must, choose a seat in the smoking section.
(4)以must开头的一般疑问句,若要作否定回答,常用needn’t或haven’t to,一般不用mustn’t。
A: ---Must e at four o’clock?
B: ---Oh, no. You needn’e at four.
4. ought to/should
(1)意为“应该”,表义务或责任, ought to的语气比should稍重。
It’s nearly seven o’clock. Jack should be here at any moment.
(2)should表“竟然、万一”。
You can’t imagine that a well—behaved gentleman should be so rude to a lady.
If you should have any difficulty in getting spare parts, ring this number.
5. need
(1)意为“需要”,作情态动词用时,须跟动词原形,无人称、数、时态的变化,一般只用于否定句或疑问句中。在肯定句中一般用作行为动词。
---I don’t mind telling you what I know.
---You needn’t. I’m not asking you for it.
I don’t think he need buy a puter.
(2)以need开头的一般疑问句,若要作肯定回答,常用must,一般不用need。
---Need e?
---Yes, you must.
6. dare
意为“敢”,作情态动词用时,须跟动词原形,有过去式(dared),无人称、数的变化,主要用于否定句、疑问句或条件句中。在肯定句中一般用作行为动词。
I wonder how he dared s