剑桥MSE基础语法丨情态动词的作用（下）

今天我们将继续分享：Requests, offers and invitations请求，提议，邀请、

Suggestions and obligations建议和义务

情态动词虽然数量不多，但用途广泛，今天王老师就带大家一起来从情态动词的作用着手，一起拿下情态动词吧！

情态动词的作用：

Probability可能性

Ability能力

Permission准许

Requests, offers and invitations请求，提议，邀请

Suggestions and obligations建议和义务

4：Requests,offers and invitations请求,提议,邀请

Requests

我们使用could you .../would you ...来礼貌地告知、请求别人做某事：

Could you take a message, please?

Would you carry this for me, please?

同样可使用can/will请求别人做某事，但礼貌程度略有降低：

Can you take a message, please?

Will you take a message, please?

offers and invitations

我们使用can I... /shall I...来进行提议：

Can I help you?

Shall I help you with that?

有时也用I can/I could/I will来提议：

I can do that for you if you like.

I could give you a lift to the station.

I'll do that for you if you like.

I'll give you a lift to the station.

我们使用Would you like (to)...表示邀请：

Would you like to come round tomorrow?

Would you like another drink?

5：Suggestions and obligations建议和义务

Suggestions

我们使用should/could/shouldn't来给建议

You should send an email.

We could meet at the weekend.

You shouldn't go by train.

注意！could一般用在给出积极建议的时候。

obligations

我们使用must/mustn't/have to表达义务、必须做/不做某事：（have to严格来讲不算情态动词哦，但用法接近情态动词，所以可以一起学习）

You must stop at a red light.

I'm sorry, but you mustn't make a noise in here.

You have to go to the meeting.

注意！当在给出命令或强烈建议时通常使用must；在说到规则规定的时候通常使用have to。

如果涉及过去的话，则使用had to/couldn't表示义务：

Everyone had to bring some food to the meeting.

You couldn't make a noise in the library.

That's it! 这就是情态动词的基本用法啦！一些情态动词如can/could, must, may在这此出镜率超高，小朋友们需要重点学习记忆~

最后的最后还要强调一点：

情态动词后接动词原形！

情态动词后接动词原形！

情态动词后接动词原形！