and How can I help you?; How can I serve you?; May I help you?; What Can I do for you?
In what way can I serve you? (Usually said by store clerks and food service personnel. The first question is the most polite, and the last is the least polite.) Waiter: How can I help you? Sue: I'm not ready to order yet.Clerk: May I help you? Jane: I'm looking for a gift for my aunt.