IN: Which person is he?
Joe earned more money than Rob on the Price is Right because he kept guessing wrong.
OUT: Rob

IN: Which person is they?
The preservation society managed to rescue a rare species of birds so they will have the chance to survive.
OUT: a rare species of birds

IN: Which person is he?
John appreciated Bill because he had been in need.
OUT: John

IN: Which person is they?
My parents gave the neighbors tickets to Six Flags since they had extras.
OUT:
My parents