English Grammar Reference: Giving advice

When someone has a problem, we can give them advice in the following ways:

"I have a headache."

You should take some medicine.

Subject	should	base form
You	should	study	more.
You	shouldn't	smoke	so much.

You ought to take some medicine.

Subject	ought to	base form
You	ought to	do	more exercise.
You	oughtn't to	think	so negatively.

Why don't you take some medicine?

Why don't you	base form
Why don't you	take up	jogging?
Why don't you	have	a holiday?

If I were you I'd take some medicine.

If I were you I'd	base form
If I were you I'd	stop	smoking.
If I were you I'd	drink	less whisky.