1.

　　People sometimes say Madam as a very formal and polite way of addressing a woman whose name they do not know or a woman of superior rank. For example, a shop assistant might address a woman customer as Madam .

　　2.

　　You use the expression 'Dear madam' at the beginning of a formal letter or a business letter when you are writing to a woman.

　　3.

　　Madam is sometimes used in front of words such as 'Chairman' to address the woman who holds the position mentioned.

　　4.

　　You can call a little girl a madam if you are annoyed because she is being naughty and behaving as if she expects other people to do what she wants.