情态动词dare通常用于疑问句，否定句和条件状语从句中，表示“敢”的意思：
Dare he swim across the river? 他敢游过这条河吗?
He dare not come to see me. 他不敢来见我。
I dare not say so. 我不敢这样说。
She dare not go out of the house. 她不敢走出房间。
How dare you be so rude! 你竟敢如此无礼!
If you dare speak to me like this again, you’ll be sorry. 如果你胆敢再和我那样说话，你会感到遗憾的。
实际上，在现代英语中，dare往往用做实意动词：
Do you dare to ask her? 你敢问她吗?
He didn’t dare to go. 他不敢去。
I would never dare to jump down from the wall. 我永远也不敢从那堵墙上跳下来。
Does anyone dare to call me a liar? 有谁敢说我是个说谎者吗?
（六）should/ought to的用法
两者大多数情况下可以互换。
1、表示道义上的责任，义务或要求，有时表示劝告。ought to的否定式为ought not to /oughtn’t to。如：
You ought to /should pay more attention to what your lawyer says. 你应该更多的注意你律师的话。
They shouldn’t allow parking here. The street is too narrow. 这里不应该允许停车，街道太窄了。
This word is spelt wrongly. There should be another “s”.
这个词拼写错了，还应该有一个 “s”。
I should go slowly here. It’s a built-up area. 这里我应该慢点儿走。这个地区建筑物多。
2. 表示推测和可能性，是“应该”之意。 表示对现在和将来的推测。
You ought not to/shouldn’t be sleeping now. It’s already eight o’clock. 你不该还在睡觉，都已经八点了。
This pen ought to /should be yours. 这支笔应该是你的。
If the train is up to time, John should/ought to be here any minute now. 如果火车晚点的话，JOHN现在马上就应该到了。
3、“should/ought to have+过去分词”表示对过去的推测，意 思 是“应该已经”。有时表示“应该做而没有做”，是“本应该”的意思;“should not/ought not to have+过去分词”表示“做了不应该做的事情”，是“本不该”的意思，因而它们都含有责备的语气：
He began two hours ago. He ought to have finished filling in the forms now. 两个钟头前他就开始了，现在应该填完那些表格了。
One should have been asleep and the other on watch. 本应该一个睡觉，另一个站岗。.
You should not have asked him for help. 你本不应该向他求助。
4、表示讲话人惊奇，失望，愤怒等感情：
What’s happened to that money? How should I know? 那些钱怎么了?-我怎么知道?
It’s strange that he should have lost his temper for such trivial things as that. 真奇怪，他竟然为这么小的事情发脾气。
Why should I believe you? 我为什么要相信你?
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