Whose cellphone is this?
It's Ana's cellphone.
Whose bedroom is this?
It's Jenny's bedroom.
Whose couch is this?
It's my neighbor's couch.
Whose burger is this?
It's my sisters' burger.
Whose pizza is this?
It's my friends' pizza.
Whose bed is this?
It's my cousin's bed.
Whose cellphone is this?
It's Ben's bike.
Whose video game is this?
It's Josh's video game.