la sua fiducia

his/her trust

→ il
phrase Rare #33,228
his/her trust “Sua” can refer to a man or a woman; the article “la” agrees with “fiducia.”
IT: Devi guadagnarti la sua fiducia.
EN: You have to earn his/her trust.

Vi dovete guadagnare la sua fiducia.

You have to earn his trust.

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)

Hai tradito la sua fiducia.

You betrayed his trust.

— Lo Hobbit: La desolazione di Smaug (2013)

Ti devi guadagnare la sua fiducia.

You have to earn his trust.

La sua fiducia cominciò a crescere.

His confidence began to grow.

No, la sua fiducia.

No, his trust.

— Il conformista (1971)