2015新版广州小学六年级英语U7 It is the polite thing to do

U7 小学六年级下新教材 第八次

语法讲练

情态动词

一. 情态动词有

can (could), _____________________ may (might), _____________________ must, _____________________ have to,(had to) _____________________ shall (should) _____________________ will (would) _____________________

二．怎样使用情态动词？

1. 情态动词无人称和数的变化；

例如： I can do it. He can do it. You can do it. 2. 不能单独使用，必须与其后的动词原形构成谓语 例如： I can do it.

三．具体讲解

一）、 can, could 1) 表示能力。

Can you lift this heavy box?

Mary can speak three languages. Can you skate? 2) 表示请求和允许。 -----Can I go now?

----- Yes, you can. / No, you can’t.

此时可与may互换。在疑问句中还可用could, might代替，不是过去式，只是语气更委婉，不能用于肯定句和答语中。 ---- Could I come to see you tomorrow? ---- Yes, you can. ( No, I’m afraid not. )

3) 表示推测（惊讶、怀疑、不相信的态度），用于疑问句、否定句和感叹句中。 Can this be true?

This can’t be done by him. How can this be true?

二、 may, might

1) 表示请求和允许。might比 may语气更委婉，而不是过去式。否定回答时可用can’t 或mustn’t，表示“不可以，禁止”。 ----Might/ May I smoke in this room? ---- No, you mustn’t.

---- May/Might I take this book out of the room? ---- Yes, you can. (No, you can’t / mustn’t. )

U7 小学六年级下新教材 第八次

2）用于祈使句，表示祝愿。 May you succeed!

3) 表示推测、可能性（不用于疑问句）。

might不是过去式，它所表示的可能性比may小。 1．He may /might be very busy now.

2．Your mother may /might not know the truth.

三、 must, have to 1) 表示必须。

You must come in time. 2) have to则强调”不得不”。

I had to work when I was your age.

四、 shall, should 表示“应该”

1) shall 用于第一人称，征求对方的意见。 What shall we do this evening? 2) should

1. I should help her because she is in trouble. 1. You should go to class right away. 2. Should I open the window?

练习：should 练练看

1. keep quiet, at the library.

eg. We should keep quiet at the library. 2. stand in line, at the bus stop.

3. let the old people take the seat, on the bus. 4. help the young, when they’re in trouble. 5. talk loudly, in the public place. 6. waste water

7. talk when others are talking

1. Be quiet

2. play in class when the teacher is talking 3. wait until you finish 4. talk with your mouth full 5. share with others

6. takall the food from the dish 7. be kind

8. laugh at another pupil

8. throw things on the ground

六、 will, would

1) 表示请求、建议等，would更委婉。

Will / Would you pass me the ball, please? 2) 表示意志、愿望和决心。 1. I will never do that again.

U7 小学六年级下新教材 第八次

小试牛刀

(一) 单项选择。