ought to

Universal Words modal verb (negative ought not to, short form especially BrE oughtn't to) 1 used to say what is the right thing to do: They ought to apologize. * 'Ought I to write to say thank you?' 'Yes, I think you ought (to).' * They ought to have apologized (= but they didn't). * Such things ought not to be allowed. * He oughtn't to have been driving so fast. -< SHOULD 2 used to say what you expect or would like to happen: Children ought to be able to read by the age of 7. * Nurses ought to earn more. 3 used to say what you advise or recommend: We ought to be leaving now. * This is delicious. You ought to try some. * You ought to have come to the meeting. It was interesting. 4 used to say what has probably happened or is probably true: If he started out at nine, he ought to be here by now. * That ought to be enough food for the four of us. * Oughtn't the water to have boiled by now? -> MODAL