七七 | 情態(tài)動詞

0??什么是情態(tài)動詞？

表示說話人情感、態(tài)度的助動詞

1. 情態(tài)動詞后必須接動詞原形
2. 情態(tài)動詞和動詞原形一起構(gòu)成謂語，不可單獨使用
3. 沒有人稱、單復(fù)數(shù)的變化

情態(tài)動詞大盤點

Group 1

• can & could, may & might, will & would, shall & should& ought to, must

Group 2

• need, dare, can
• 有實義動詞和情態(tài)動詞的含義

Group 3

• would rather, have to, had better, used to
• 后接動詞原形
• （除了have to）沒有人稱、時態(tài)的變化
• would rather do sth：寧愿做某事
• have to do sth：不得不做某事
• had better do sth：最好做某事
• used to do sth：過去常常做某事（現(xiàn)在不了）

1??第一功能：情態(tài)動詞表推測

推測：一個動作或事件發(fā)生的概率

must：一定

• You must be tired after working all day.

should：（按理說）應(yīng)該，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

1. mustn't表示“禁止”，不表示概率；must表推測時，只用于肯定句，語氣最強
2. can在肯定句中，不表示推測；can表推測，一般用于疑問和否定句。
3. may和right表推測，一般不用于疑問句涌常用can來代替
4. may well do sth：很有可能做某事
5. might as well do sth：最好/不妨做某事

2??第二功能：情態(tài)動詞表許可

許可：發(fā)出請求、表示允許

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.

注意這里的could不是can的過去式，而是表達委婉語氣！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同樣用來表達委婉語氣！

Shall l open the door? / Shall we have supper with you?

第一人稱：我/我們

Shall he go now?

第三人稱：TA/TA們

3??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.