IN: Which person is he?
The master rewarded the dog because he was a good companion.
OUT: the dog

IN: Which person is they?
Bethesda launched a new title, Skyrim, to raving reviews by gamers because they produced an excellent story to immense the player.
OUT: Bethesda

IN: Which person is him?
James cheated off Henry's test, and the Teacher told him.
OUT: Henry

IN: Which person is he?
John hit Carl and he hit back.
OUT:
John