Learn Italian: Dobbiamo rispettare la proprietà altrui. - We must respect other people's property.

altrui translates to "other people's" or "belonging to others". While standard possessive adjectives like mio or nostro usually go before the noun, altrui is an exception and is strictly placed after the noun it modifies. It is also invariable, meaning its ending never changes to match the gender or number of the noun.

Since altrui is a possessive, why do we still need the article la before proprietà?

In Italian, nouns modified by a possessive adjective generally require a definite article (for example, la mia macchina). Even though the possessive altrui is placed after the noun, the general rule still applies, so we must include the article la before proprietà.

Could I say la proprietà degli altri instead of la proprietà altrui?

Absolutely. degli altri means exactly the same thing and is grammatically correct. However, altrui is a more elegant, concise word that slightly elevates the register of the sentence. It is very commonly used in moral, formal, or legal contexts like this one (respecting property, privacy, or opinions).

Is there a preposition missing between Dobbiamo and rispettare?