their reasons
Él tiene sus razones para quedarse allá.
He has his reasons for staying there.
Como dijo A Gui, todo el mundo tiene sus razones.
As A Gui said, everyone has their reasons.
— Kung fu (2004)
State your reasons.
Pero reconozco que debe haber tenido sus razones.
But I admit he must have had his reasons.
She explained her reasons to us.