Laban Dictionary - Từ diển Anh Việt, Việt Anh

[modal verb]

Ought is almost always followed by to and the infinitive form of a verb. The phrase ought to has the same meaning as should and is used in the same ways, but it is less common and somewhat more formal. The negative forms ought not and oughtn't are often used without a following to.

used to indicate what is expected

used to say or suggest what should be done