should/ought to/had better
There are three auxiliary verbs that you can use to give advice. They are should, ought to, and had better.
You should put cool water on a burn. You ought to put cool water on a burn. You had better put cool water on a burn.
Although all three have the meaning of should, "had better" is stronger because it implies a negative consequence if you don't follow the advice. Another difference is that usuallyought to and had better are not used with questions.
Should I put cool water on a burn? Ought I to put cool water on a burn? Had better I put cool water on a burn?
There is a difference in the negative form as well. You can make a contraction only with the verb should, not the other two (see examples below). Also, note the position of the word not in the negative sentence below. The word not goes after should and had betterbut in the middle of ought to ("ought not to").
