【英语语法系统合集】情态动词学得好，情商低不了！
七七 | 情态动词
0️⃣什么是情态动词？
表示说话人情感、态度的助动词
- 情态动词后必须接动词原形
- 情态动词和动词原形一起构成谓语，不可单独使用
- 没有人称、单复数的变化
情态动词大盘点
Group 1
- can & could, may & might, will & would, shall & should& ought to, must
Group 2
- need, dare, can
- 有实义动词和情态动词的含义
Group 3
- would rather, have to, had better, used to
- 后接动词原形
- （除了have to）没有人称、时态的变化
- would rather do sth：宁愿做某事
- have to do sth：不得不做某事
- had better do sth：最好做某事
- used to do sth：过去常常做某事（现在不了）
1️⃣第一功能：情态动词表推测
推测：一个动作或事件发生的概率
must：一定
- You must be tired after working all day.
should：（按理说）应该，可能
- he bus should arrive in a few minutes.
could：可能
- This could be the best way to solve the problem now.
may：可能
- That may be true.
might：可能
- He might get here in time, but l can't be sure.
might not：可能不
- l might not go. lt depends on how tired l am.
may not：可能不
- l may not have her new telephone number; let me check.
could not：不太可能
- He couldn't be over fifty. He looks so energetic.
can not：肯定不
- That can't be Mary. She's in hospital.
注意
- mustn't表示“禁止”，不表示概率；must表推测时，只用于肯定句，语气最强
- can在肯定句中，不表示推测；can表推测，一般用于疑问和否定句。
- may和right表推测，一般不用于疑问句涌常用can来代替
- may well do sth：很有可能做某事
- might as well do sth：最好/不妨做某事
2️⃣第二功能：情态动词表许可
许可：发出请求、表示允许
Can l use your phone, please?
- Yes, you can/may.
- No, you can't.
Could you go a little slower?
- Yes, you can/may.
- No, you can't.
注意这里的could不是can的过去式，而是表达委婉语气！回答不用could！
May l put my bike here?
- Yes, you may/can.
- No, you can't.
- No, you mustn't.
Will you sing us a song?
Would you mind closing the window?
would同样用来表达委婉语气！
Shall l open the door? / Shall we have supper with you?
第一人称：我/我们
Shall he go now?
第三人称：TA/TA们
3️⃣肯否不一
Mum, must l do my homework tonight?
肯定回答
- Yes, you must.
否定回答
- No, you needn't.
- No, you don't have to.
Can l go out?
肯定回答
- Yes, you can/may.
否定回答
- No, you can't.
May l take this book out of the reading room?
肯定回答
- Yes, you can/may.
否定回答
- No, you can't.
- No, you mustn't.
