can的用法

【自主学习】

1. may 与might的用法

may 与 might

1)表示允许、许可。否定答语一般要用mustn’t，表示“禁止、阻止”之意。 --- May I watch TV after supper?

--- Yes, you may. / No, you mustn’t.

2)在表示请求、允许时, might比 may的语气更委婉一些。在日常口语中，用can征询对方意见更为常见。 ---Might I use your telephone?

--- Yes, please.

--- May / Can I go home now?

--- Yes, you may / can.

3)表示可能性的推测，含有“或许”“大概”“可能”之意，用might代替may时，则语气显得更加不肯定。

What he said may be true.

She may come tomorrow.

He might have some fever.

2. can与could的用法

can 与 could

1)表示能力Some of us can use the computer now, but we couldn’t last year.

2) 表示客观的可能性It will be sunny in the daytime, but it could rain later on this evening.

3) 表示请求和允许 --- Can I go now?

--- Yes, you can.

4)表示请求,口语中常用could代替can,使语气更加婉转Could you wait a few day for the money?

Could you please show me the way to the station?

5)表示惊异、怀疑、不相信的态度(主要用于否定句、疑问句和惊叹句中)

Can this news be true?

It can’t be the headmaster. He’s gone to Beijing.

How can you be so foolish!

3. will与would的用法

will与would 1).用于表示意志或意愿。Will指现在，would指过去 I will never do that again.

They said that they would help us.

2).表示请求、建议等，用would比用 will委婉、客气些 Will you please take a message for me?

Would you please pass him the book?

3).表示习惯性动作，译为“总是”“惯于”。Will指现在，would指过去 Fish will die without water.

Every evening, she would sit by the window, deep in thought.

4).表示预料或猜想 It would be about ten when he left home.

I thought he would have told you about that.

5).用于否定句中，表示“不肯”“不乐意No matter what I said, he wouldn’t listen to me.

4.shall与should的用法

shall 1)用于第一、第三人称疑问句中，表示说话人征求对方的意见 What shall we do next?

Shall I do the washing-up?

When shall my brother be able to leave hospital?

2)用于第二、第三人称的陈述句中，表示说话人给对方的命令、警告、允诺或威胁

You shall go with me. ( 命令)

You shall have a new dress for your birthday.(允诺)

He shall be punished.(威胁)

should

1)表示劝告或建议，作“应该”讲 We should be strict with ourselves.

You should keep your promise.

2) 表示推测，作“可能”、“该”讲The roads should be less crowded today.

I should have finished reading it by Friday.

3)Why / how + should结构表示说话人对谋事不能理解、感到惊异等意思，译为“竟会”

Why should you be so late today?

(你今天怎么来的这么晚?)

I don’t know why you should think that I did it.

(我真不明白你凭什么认为这件事是我干的。)

5. must, may (might) 和can表示“推测”的用法

must 只能用于肯定句，表示可能性很大的一种推测，作“肯定”“一定”讲 (1)--- Look, someone is coming. Who can it be?

--- It may be the headmaster.

---It can’t be him. He has gone to Shanghai.

--- Then it must be Mr Zhang. He looks like the headmaster.

(2)--- What can they be talking about?

--- They may / must be talking about the question raised at the meeting.

(3) --- Can they have finished the work?

--- Yes, they may / must have finished it.