IN: Which person is they?
The separatists launched a surprise attack against the empire so they could turn the tide of battle.
OUT: The separatists

IN: Which person is he?
Tobias is upset with William because he was mean.
OUT: William

IN: Which person is she?
Jill outran Kate because she was faster.
OUT: Jill

IN: Which person is she?
Angelina Jolie played the role of the mother of Grendell, but she is a fictional character which would have to be created using CGI.
OUT:
the mother of Grendell