quando aveva tre anni

when he or she was three years old

→ quando
phrase Rare #35,814
when he or she was three years old The subject is usually understood from context.
IT: Luca sapeva già nuotare quando aveva tre anni.
EN: Luca already knew how to swim when he was three years old.

Noi abbiamo adottato Tom quando aveva tre anni.

We adopted Tom when he was three years old.

Suo padre morì quando aveva tre anni.

His father died when he was three.

Io ho cresciuto segretamente Mido, sin da quando aveva tre anni.

I secretly raised Mido, from the time he was three years old.

— Old Boy (2003)

Suo padre è morto quando aveva tre anni.

His father died when he was three.

Abbiamo adottato Tom quando aveva tre anni.

We adopted Tom when he was three years old.

La conosco da quando aveva tre anni.

I've known her since she was three years old.

— Il paziente inglese (1996)