小学英语情态动词

小学英语教案——情态动词

情态动词本身有各种意义，但不能单独作谓语，只能和主要动词一起构成谓语，表示说话人的语气和情态，这样的动词称为情态动词。情态动词没有人称和数的变化。

常用的情态动词有can, could, may, might, will, would, should, must, need, dare等。

一、can, could的用法

1. can的用法

（1）表示能力、许可、可能性。

如：Can you speak English? 你会讲英语吗？

Can you play the piano? 你会弹钢琴吗？

She can swim fast, but I can't. 她能游得快，但我不能。

I can see with my eyes. 我用眼睛看。

（2）表示请求或者许可。

如：Can I help you? 我能帮助你吗？You can't play basketball. 你不能玩篮球。

Can you...？“请你……好吗？”表示说话人的请求；Can I...？“我可以……吗？”用来征求对方是否允许自己做某事。如在句末加上please一词就显得更有礼貌了。例如：Can you help me, please? 请你帮助我好吗？

You can use my dictionary. 你可以用我的字典。

（3）表示推测，意为“可能”，常用与否定句和疑问句中，此时can't译为“不可能”。

如：Can the news be true? 这个消息会是真的吗？

The moon can't always be full. 月亮不可能常圆。

2. could的用法

，表示过去的能力、可能性或允许：能、会”）（1can的过去式，意为“He could write poems when he was 10. 他十岁时就会写诗。如：I could run faster then.那时我能跑得更快。It could be no better at that time.那时好得不能再好了。没有过去的意思。2）在疑问句中，表示委婉的语气，此时could （Could you do me a favour? 你能帮我个忙吗？如：

的用法二、may, might5of 1 Page

都表请求或允许，might可以指过去时间，也可指现在时间，语气更委婉。1.

如：You may take whatever you like. 你喜欢什么就拿什么。

May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗？May I come in？我可以进来吗？Yes, please. / may引起的问句时，多避免用这个词，而用其它方式，如在回答以

以免显得太严峻或等，Certainly. / Please don't ./ You'd better not. / No, you mustn't. 不客气。，表示可能。2 我明天可能会比较忙。I may be busy tomorrow.

Exercise

1. -Is John coming by train? --He should, but he __________ not. He likes driving his car.

A. must

B. can

C. need

D. may

2. Peter __________ come with us tonight, but he isn't very sure yet.

D. will A. mustB. canC. may I thought you __________ be hungry, so I have brought you some cakes. 3. D. could C. can B. might A. may

的用法三、must, have to must 表示说话人主观上的看法，即主观上的必要。have to “1. 两词都是必须”的意思，表示客观的需要，My brother was very ill, so I had to call the doctor in the middle of the night.如：

客观上需要做这件事)我弟弟病得很厉害，我只得半夜里把医生请来。( He said that they must work hard. 他说他们必须努力工作。（主观上要做这件事）

只有一种形式。must2. have to有人称、数、时态的变化，而如：He had to look after his sister at home yesterday. 昨天他不得不在家照看妹妹。

不必”在否定结构中：3. don't have to表示“mustn't禁止“表示”，你不一定要把此事告诉他。如：You don't have to tell him about it. 你一定不要把这件事告诉他。You mustn't tell him about it. —Must I finish the homework right now? 我现在必须完成家庭作业吗？—Yes, you must. / Yes, you have to. 是的。

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(—No, you needn't. / No, you don't have to. 不，不必。)

4. must be+表语，表示推测，它的否定和疑问形式用can代替must。

如：This must be your pen. 这个一定是你的钢笔。

Your sister must be a doctor in this hospital.你姐姐一定是这家医院的医生。

Exercise

1. Come on! We __________ hurry because there isn't much time left.

A. may

B. must

C. can

D. need

2. Amy did best in the English test. She __________ hard last week.

A. must have been working

B. should have worked

D. must work.

C. should work

四、should的用法