七. ought to的用法。

1. ought to表示应该时意义与should基本一致，但更侧重于一种义务或责任。

You ought to take care of him.

Parents ought to bring up their children.

2. 表示推测，注意与must表示推测时的区别。

He must be home by now.

He ought to be home by now.

This is where she must be.

This is where she ought to be.

3. ought to have done的用法与should have done的用法相同

注意：ought to在美国英语中，用于否定句和疑问句时，to可以省略。如：

Ought you smoke so much?

You oughtn’t smoke so much.

八. used to; had better; would rather的用法。

1. used to表示过去习惯动作或状态，现在已经不存在，在间接引语中，其形式可不变。如：He told us he used to play football when he was young.

1) 在疑问句、否定句或否定疑问句中，可有两种形式。

疑问句：Did you used to/Used you to go to the same school as your brother?

否定句：I usedn’t to/didn’t use to go there. (usedn’t 也可为usen’t, 发音不变)。

否定句疑问句：Usedn’t you to/Didn’t you used to be interested in the play?

2) 在附加疑问句和简略答语中，也可有两种形式。

She used to be very fat, didn’t/usedn’t she?

— Did you used to/Used you to play chess? — Yes, I did/used to.

2. had better意为“最好”，后接不带to不定式。

We had better go now.

Hadn’t we better stop now?

I think I’d better be going.

You had better have done that.

3. would rather意为“宁愿”，表示选择，后接不带to的不定式。

I’d rather not say anything.

Would you rather work on a farm?

— Wouldn’t you rather stay here? — No, I would not. I’d rather go there.

由于would rather表选择，故后面可接than.

I would rather watch TV than go to see than go to see the film.

I would rather throw it away than you should get it.(若than后面接从句常用should do)

I’d rather you didn’t talk about this to anyone.

※ would rather 还可写为would sooner/would as soon.