UK TV and movies use "sir" and "ma'am" (or "marm") pretty frequently. In the U.S., they're not so commonly used outside of very formal service situations (e.g.

UK TV and movies use "sir" and "ma'am" (or "marm") pretty frequently. In the U.S., they're not so commonly used outside of very formal service situations (e.g., military, customer service). Friends don't call each other "sir" or "ma'am", except perhaps as a joke.