Imagine yourself – a man – sitting next to someone you want to talk to – a woman – on a bus, train, plane, etc. After a while you say: 'One of us has to start talking / break the ice, don't they? / ...
Here's a conversation. "I saw a salesperson there" "Was it a girl?" Is it OK to use "it" when you refer to the salesperson? Or should you use "that" instead of "it"?
Suppose I see someone coming whose gender is unknown; how should I ask who the approaching person is? Should I say “Who is he?”