外研2003课标版《Grammar》精品PPT课件优质课下载

外研2003课标版《Grammar》精品PPT课件优质课下载

(1)表示能力(could常用于过去的能力)

The police still haven’t found the missing child, but they’re doing all they can.

考点1 9大情态动词的基本用法

1. can/could

(1)表示能力(could常用于过去的能力)

The police still haven’t found the missing child, but they’re doing all they can.

(2)表示理论上的可能性, “有时候可能会”(用在肯定句中)

It can be quite windy there, especially in spring.

(3)表示请求和允许, 口语中常用could代替can(could用来表示现在, 用以委婉地提出请求等, 但回答时必须用can)

Could you tell me how I can get to the railway station?

(4)表示推测“可能”(用于否定句、疑问句中)

Just be patient. You can’t expect the world to change so soon.

2. may/might

(1)表示请求、允许、许可, might比may的语气更委婉

—May I take the book out?

—I’m afraid not.

(2)表示推测“可能”, 可能性比can/could小

—I don’t really like James. Why did you invite him?

—Don’t worry. He might not come. He said he wasn’t certain what his plans were.

3. must

(1)表示“必须; 应该”

—Shall I inform him of the change of the schedule right now?

—I am afraid you must, in case he comes late for the meeting.

(2)表示“偏要, 硬要”做某事

If you must go, at least wait until the storm is over.