Modals of Advice

Should and shouldn't for advice:

Should is a modal verb. It has the same form for all persons and you don't use the auxiliary do in questions and negatives.
You use should + the simple form of a verb to give advice.

You should take some exercise on long flights.
You shouldn't drive fast.

Questions	Short answers
*Should* I take some exercise? *Should* I drive fast?	Yes, you *should. No, you shouldn't*.

Should(n't) and ought(n't) to mean the same. (Ought to is a bit old fashioned).

You ought to take some exercise on long flights.