Dare is used both as an ordinary verb and as an auxiliary verb. The ordinary verb dare is used in the sense of defy, challenge or face boldly. It has -s in the third person singular. Questions and negatives are made with do.
- He did not dare to accept the challenge.
- He dares you to do it.
As an auxiliary verb dare is uninflected. It doesn’t change its form whatever be the number and person of its subject. The auxiliary dare is commonly used in questions and negative sentences. It is not very common in affirmative clauses.
- He dare not do such a thing.
- How dare you contradict me?
- He dare not accept the challenge.
- Dare he say that to you?
- How dare he do such a thing?
The expression ‘I dare say’ now just means ‘perhaps’.
- I dare say he will agree to our proposal. (He will perhaps agree to our proposal.)
- I dare say that you are wrong.
Had better has similar meaning to should and ought.
- You had better consult a doctor. (= You should consult a doctor.)
- You had better get some rest. (= You should get some rest.)
Had better may also express a threat.
- He had better be careful.