his/her/your/their cell phone
Tom olvidó en dónde puso su celular.
Tom forgot where he put his cell phone.
Sabes donde está su celular, ¿no es así?
You know where his cell phone is, don't you?
— Madre (Madeo) (2009)
Tom dice que tiene miedo de que su celular sea más inteligente que él.
Tom says he’s afraid that his cellphone might be smarter than he is.
Estaba tumbado en la cama mirando videos en su celular.
He was lying in bed watching videos on his cell phone.
Llamé a su celular y me colgó.
I called his cell phone and he hung up on me.
— Guardianes del día (2006)
Siempre está perdiendo su celular.
He’s always losing his cell phone.