Asking questions is an essential part of police investigation. In the ordinary sense a police officer is free to ask a person for identification without implicating the Fourth Amendment.
“I must be the only player in the world who ever injured himself for a tournament by stepping on a shell on the beach. I don't know what I'm going to do.”
“I was always the kid on scholarship, I was a soloist with my company, I'd been working with the symphony since I was 14.”