IN: Which person is he?
John flicked Bill because he saw a fly on his shirt.
OUT: John

IN: Which person is he?
Knight Commander Roddick was plagued by a vision of his dead son because he was killed due to a lack of protection from his father.
OUT: his dead son

IN: Which person is they?
Black Eyed Peas hosted a huge event for the partners of Intel, since they have lots of money to hire them to perform.
OUT: the partners of Intel

IN: Which person is they?
Retail stores have been trying to pass an internet tax on online retailers for the past few years, but they are adamant on fighting against this regulation they are trying to impose.
OUT:
online retailers