Should, ought to, and had better are used to give advice or recommendations.
Should is the most common and versatile. It is used to express a general recommendation or what is considered to be the best course of action.
Ought to is more formal than should and implies a stronger sense of duty or obligation. It suggests that something is the right or moral thing to do.
Had better expresses a strong warning or that there will be negative consequences if the advice is not followed. It is often used in urgent situations or when there is a risk of something bad happening.
Here are some examples of how to use should, ought to, and had better to express advice:
* You should see a doctor about that cough.
* You ought to be more careful with your money.
* You'd better apologize to her before it's too late.
The choice of which modal verb to use depends on the specific situation and the strength of the advice you want to give.