ought */*/*/

UK [ɔːt] / US [ɔt] modal verb

Summary:

Ought is usually followed by "to" and an infinitive: You ought to tell the truth. Sometimes it is used without "to" or a following infinitive in a formal way: I don't practise as often as I ought. It is also used in an informal way followed by "to" but no following infinitive: I don't spend as much time with them as I ought to.
Ought does not change its form, so the third person singular form does not end in "-s": She ought to try a little harder. Questions and negatives are formed without "do": You ought not to be here. ♦ Ought I to tell my parents? The negative short form oughtn't can also be used, and this is less formal. There is no past tense but ought to have can be used for referring to actions that did not happen but should have, or to actions that have probably happened: I ought to have come earlier. ♦ They ought to have arrived by now.
Usage note:
Should can be used in the same way as ought to and is more common, especially in negatives and questions.

1) used for saying what is the right or sensible thing to do, or the right way to behave

ought to (do something):

You ought to get up earlier.

There ought to be a ban on cigarette advertising.

Teachers ought not to swear in front of the children.

We don't exercise much, but we really ought to.

2) used when you have strong reasons for believing or expecting something

ought to (do something):

It's a game that the French team ought to win.

ought to have done something:

The meeting ought to have finished by three o'clock.

•

ought to have (done something) — used when you realize that someone did not do the right thing in the past

You ought to have listened to the warnings.

I know I ought not to have taken the money.

you ought to see/hear/meet etc — used for emphasizing how good, impressive, or unusual something or someone is

You ought to see their new house – it's enormous.