You say please when you are politely asking or inviting someone to do something.

You say please when you are accepting something politely.

You can say please to indicate that you want someone to stop doing something or stop speaking. You would say this if, for example, what they are doing or saying makes you angry or upset.

You can say please in order to attract someone's attention politely. Children in particular say 'please ' to attract the attention of a teacher or other adult.

If someone or something pleases you, they make you feel happy and satisfied.

You use please in expressions such as as she pleases ,whatever you please, and anything he pleases to indicate that someone can do or have whatever they want.

You can use as you please in expressions such as bold as you please or casually as you please or charming as you please in order to emphasize what you are saying.

If you please is sometimes used as a very polite and formal way of attracting someone's attention or of asking them to do something.

You can say if you please to indicate that a situation surprises or annoys you, or is difficult to believe.

You say 'please yourself ' to indicate in a rather rude way that you do not mind or care whether the person you are talking to does a particular thing or not.