his/her trust
Ti devi guadagnare la sua fiducia.
You have to earn his trust.
Vi dovete guadagnare la sua fiducia.
You have to earn his trust.
La sua fiducia cominciò a crescere.
His confidence began to grow.
Avresti dovuto lasciarlo fare e avresti ancora la sua fiducia.
You should have let him do it and you would still have his trust.
— Mission: Impossible - Rogue Nation (2015)