IN: Which person is he?
John tried to bake with Michael, but he said "I don't like kitchens!"
OUT: Michael

IN: Which person is they?
Policemen advocated the use of wire taps to track terrorists, because they could not catch them without those tools.
OUT: Policemen

IN: Which person is they?
Some citizens of the kingdom were put in chains by the royal guard since they have been accused of breaking the law.
OUT: Some citizens of the kingdom

IN: Which person is he?
Technician Stepanic crafted advanced opticals for Leforge, but he would still prefer to see without such devices.
OUT:
Leforge