一、ought to 的用法
(1)表示责任和义务，意为“应该”，与 should 同义，但语气比 should 重，侧重于“责任、义务、道德、法律”等方面。
To be a popular student, we ought to be strict with ourselves.
为了成为一名受欢迎的学生，我们应该对自己要求严格。
[名师点津] ought to 的否定形式为 ought not to (oughtn't to)；一般疑问句是将 ought 提至句首，其否定答语通常用 doesn't/don't have to 或 needn't。
—Ought he to see the doctor?
——他该去看医生吗？
—Yes, he ought to./No, he doesn't have to.
——是的，他该去。/不，他不必去。
You ought not to make this kind of mistake again.
你不应该再犯这种错误了。
(2)表示可能性，一般指较大的可能性，意为“按道理应该”。
If he started at six, he ought to be here now.
要是他6点就出发的话，这会儿该到这里了。
