情态动词ought to的用法归纳

1. 表示义务或责任

表示义务或责任，意为“应该”：

You ought to work harder. 你应该更努力工作。

Teachers ought to be honored. 教师应当受到尊敬。

Every citizen ought to obey law. 每个公民都应守法。

2. 表示建议或劝告

2. 表示建议或劝告，意为“应该”：

There ought to be more buses during the rush hour. 高峰期间应公共汽车该多发几辆。

You ought to see her new film. 你应该看看她新拍的电影。

We oughtn’t to take risks. 我们不宜于冒险。

3. 表示推断

3. 表示推断，意为“应该”、“可能”：

(1) ought to + 动词原形，表示对现在或将来情况的推测。如：

Prices ought to come down soon. 价格可能会很快下跌。

If he started at nine, he ought to be here by now. 要是他九点钟出发，现在该到了。

That ought to be enough food for all of us. 那些该够我们大家吃的了。

(2) ought to +进行式，表示对正在发生的情况的推测。如：

You oughtn’t to be talking so much. 你不该讲这么多话。

You ought not to be sitting here. It’s for old man only. 你不该坐在这儿，这是老人专座。

You ought to be wearing your shirt. 你该穿衬衫。

(3) ought to +完成式，表示对过去情况的推测；也可表示过去本该发生而实际上未发生的情况：

The table-tennis game ought to / should have finished by now. 乒乓球比赛现在应该已经结束了。

There are many books which I ought to have read, and still ought to read. 有许多书我过去就应该看的，现在还应该看。

I ought to have helped her，but I never could. 我本该帮助她的，却从未能这样做。

You ought to have come earlier. 你本该来得早一点儿。

She ought to have been a teacher. 她本该当教师。

4. ought to用于否定句和疑问句

在否定式中用ought not 或oughtn’t，在疑问中将ought提到主语之前。如：

They ought to go now, oughtn’t they? 他们现在该走了，是吗?

Ought we (to) be in Taipei by now? 他们现在大概已经到北京了吧？

—Ought I to go? 我该去吗?

—Yes, you ought (to). 对，你该去。

5. ought to与 should的用法区别

一般说来，二者可替换，只是ought to语气稍重些。如：

He ought to / should have arrived long ago. 他早就该到了。

You should / ought to have come yesterday. 你应该昨天来的。

(1) 表示因责任、义务等或表示出于法令规则、行为准则、道德责任等客观情况该做的事时，常用ought to； should则含有个人意见，强调主观看法。如：

You are his parents. You ought to take care of him. 你们是他的父母，应当管他。

They oughtn’t to let their dog run on the road. 他们不该把狗放出来满街跑。

Such things ought not to be allowed. 这类事不该允许。

(2) 在公告、须知或条例中，出于礼貌，常用should：

You should not run alongside the swimming-pool. 不准在游泳池边奔跑。