somebody/someone, everybody/everyone, anybody/anyone, nobody/no one
Our teacher told __________ to study hard for the coming exam.
__________ is in the room. The room is empty.
Does __________ want to join the club?
Does ___________want to play badminton?
Someone and somebody
Someone and somebody have no difference in meaning. Somebody is a little less formal than someone. Someone is used more in writing than somebody. Somebody is more common in speaking.