Come si usa l’aggettivo possessivo «altrui»

What does “altrui” mean in Italian?

Altrui is the tidy Italian way to say “of other people” in a single word, and its trick is that it never changes: no masculine, feminine, singular, or plural endings. Le opinioni altrui means “other people’s opinions”; le cose altrui means “other people’s things.” It usually follows the noun and saves you the longer degli altri / delle altre persone. One invariable word does all the work.

Altrui refers to one or more unspecified other people, only ever people — never objects. Pair it with proprio (“one’s own”) and you cover the whole “self vs. others” axis: rispettare le opinioni altrui, “respect others' opinions”; non prendere le cose altrui, “don’t take what belongs to others.” Because it’s invariable, you never have to match gender or number — a rare grammatical gift in Italian.