高考英语语法:高中英语语法-高一英语总复习11

高一英语总复习11

语法精讲:

情态动词(I)

had better,should,ought to

1.had better

had better的意思是"最好",后面接动词原形,表示说话人希望对方做什么。had better not则表示说话人希望对方最好不要做什么。

e.g.You had better see a doctor.

你最好找大夫看看。

You had better not go home now.

你现在最好不要回家。

2.should

should通常表示劝告,建议,意思是"应该"。

e.g.You should keep your promise.

你应该履行诺言。

You should invite him to the party.

你应该邀请他参加舞会。

3.ought to

(1)ought to常用来表示因为有责任、义务,而应该做某事,通常与should意思相近。

e.g.The students ought to obey the school rules.

学生们应遵守校规。

Oughtn't we to give him a chance to try?

我们难道不应该给他一个尝试的机会吗?

(2)ought to也常用来表示劝告或建议,意思是"应当","宜于"。

e.g.There ought to be more buses during the rush hours.

在上下班乘客拥挤的时刻,公共汽车应当多一点。

(3)ought to还可表示猜测,意思是"理应","总应该"。

e.g.If he started at seven,he ought to be here now.

要是他七点钟出发,这会儿总应该到了。

情态动词(Ⅱ)

must,have to,have got to

1. must

(1)表示"必须,应当,非……不可"。否定式是must not或mustn't,表示强烈的禁止,意思是"不得……","不准……"。

e.g.You must tell your reason.

你必须讲出你的理由。

You mustn't speak like that to your mother.

你不准像那样对你的妈妈讲话。

(2)在回答带有must的问句时,否定式常用needn't,表示"不必",语气比较委婉。

e.g.-Must I do it?

-我必须做这件事吗?

-Yes,you must.

No,you needn't.

一是的,你非做不可。

不,你不必做它。

(3)表示说话人对某事的猜测,意思是"一定","准是",只用于肯定句中。

e.g.You must be tired after the long walk.走了远路,你一定很累了。

2.have to,have got to

以上两词,都表示"必须","不得不",在这个意义上与must很相近,但must表示的是说话人的主观看法,而have,have got to则表示客观的需要,而且还有更多的时态形式。

e.g.I have to / have got to go now.

我现在得走了。

Then you will have to/ have got to go back at once.

即你得立刻回去。

He had to / had got to work day and night in the old days.

他在旧社会不得不日夜干活。