who ... it/him; the one who ... it/him
Mientras haya quien lo guarde y quien lo venda.
As long as there is someone to keep it and someone to sell it.
— Un profeta (2009)
Quien lo tiene todo debe tener también la capacidad de perderlo todo.
He who has everything must also have the capacity to lose everything.
El trabajo está disponible para quien lo solicite ahora.
The job is available to anyone who applies now.
Si ven quien lo practica, sabrán inmediatamente cómo se comporta.
If they see who practices it, they will immediately know how that person behaves.
— Ip Man (2008)
It depends on who takes it.
Quiero saber cómo se llama quien lo contrató.
I want to know the name of the person who hired him.