文档介绍：该【情态动词公开课一等奖课件赛课获奖课件 】是由【书犹药也】上传分享，文档一共【39】页，该文档可以免费在线阅读，需要了解更多关于【情态动词公开课一等奖课件赛课获奖课件 】的内容，可以使用淘豆网的站内搜索功能，选择自己适合的文档，以下文字是截取该文章内的部分文字，如需要获得完整电子版，请下载此文档到您的设备，方便您编辑和打印。The Usage of the Modal Verbs
情态动词
情态动词表达说话人对动作或状态的多种观点和态度，情态动词有词义，但不完全，是所谓的“辅助性”动词，在句中不能单独充当谓语，只能和动词原型一起构成谓语动词。 情态动词所示的情态有: 命令、容许、祈求、拒绝、愿望、乐意、义务、必要、也许、勇于、需要等。
情态动词没有人称和数的变化。
有些情态动词有过去式,有的过去式和它的原型相似。
有过去式的有:
can — could
may — might
will — would
shall — should
dare — dared
need — needed
have to — had to
过去式不变的有:
must — must
ought to — ought to
否认式：
一般都是在情态动词之后加 not
注意: ought to — ought not to
1. can, could
①表达体力或脑力方面的“能力”,或根据客观条件能做某种动作的“能力”。
The girl can dance very well.
People who don’t eat meat or fish can still stay healthy.
②在口语中, can可以表达祈求或许可。can’t 表达“不可以”。
Can I use your mobile phone for a call?
You can go home now.
Boys, you can’t play football in the street.
③用于否认句或疑问句中表达说话人对发生的事情的 “怀疑” “猜测” “不愿定”的语气。
Can the news be true?
He can’t be at home.
假如用于肯定句中，则表达抽象的或理论上的一种也许性，或表达经验之谈。
Everyone can make mistakes in his life.(人毕生中均有也许出错误)
Children can often get ill suddenly. (小孩常常也许忽然生病)
Certain things in the house can be dangerous, especially if you have young children. (家里的某些东西也许有危险，尤其是有小孩的时候)
上面两句可以看作医务工作者或抚养过孩子的人说的话，属“经验之谈”。
☆ can与be able to的区别
①can表达“能力”时，和be able to相称，许多场所都可以互相替代。但当论述过去通过一番努力才能完毕的事情或前面有特殊阐明，表达你有能力时，只能用be able to。 【误】The fire spread the building quickly but everybody could escape. 【正】The fire spread the building quickly but everybody was able to escape.
②be able to比can有更多形式。 When he grows up, he will be able to support his family.
③can常常和动词see, hear, smell, taste, feel, remember, understand等连用。
When we went into the house, we could smell something burning.
④在谈论说话时发生的动作，用can，不用be able to。 【误】Look! I'm able to swim. 【正】Look! I can swim.
④ could是can的过去式，且语气比can语气弱，更委婉。
We all knew that the young man couldn’t be a doctor. (表能力)
Could you spare one minute to explain this to me? (表征求意见)
He asked me if he could take the book out of the library. (表许可)
The news couldn’t be true. (表怀疑，不相信)
2. may, might
① may表达“容许”或“祈求”。在口语中可用can替代,但may比较正式。
May I take this magazine out?
I’d like to surf the internet for a while, may I?
② 表达说话人的猜测,认为某一事情“或许”或“也许”发生，一般只用于肯定句和否认句中。
The light isn’t on. It may be broken.
在疑问句中，表达也许性用can。
Where can he be? 他会在哪呢？
③ 表达祝愿，但语气较正式。
May our friendship be ever lasting!
④ might多在间接引语中表达过去的也许和容许。
She said that he might take her bike.
除了在间接引语中以外，might一般不表达过去的也许或者许可。如要表达过去的也许可以用could, 表达过去的许可可以用be allowed to或者had permission to。
⑤表达目前的也许，其也许性要比may小。
She might go home tomorrow.
⑥表达目前的许可,语气比may较委婉,一般用于疑问句,不可用于肯定句或者否认句。
Might I have a word with you?
☆ May I ...? 问句常见的肯定回答和否认回答：
肯定回答 否认回答
Certainly. No, you mustn't.(强烈严禁的意思)
Yes, please. No, you can't.(最常见)
Yes, of course. Please don't./You'd better not.
Sure. I don't think you can.
Go ahead, please. I'm sorry it's not allowed.