When do you use the courtesy form 'Lei' in Italian?

Question

Lei is sometimes used to indicate she, the feminine third person, but also in a special situation to address a person, irrespective of whether is a male or a female.

Answer 1

Lei means She. However, it can also mean tu (You) when addressing a person we have not been introduced to or and older person. In general it is used to emphasize that we are showing respect and courtesy to a person. Is more formal than tu.

When in doubt, I would use Lei instead than tu.