Used to ask about a person or to refer to a person already mentioned. It shows which person is doing or being something.
From Old English 'hwā', a basic question word for people. The sound shifted over time, but the role stayed the same.
Almost every language has a simple word for 'who,' because humans are obsessed with knowing about people. 'Who' is like a spotlight you can shine on any person in a sentence.
Complete word intelligence in one call. Free tier — 50 lookups/day.