Learn Finnish: Tämä auto on teidän.

In Finnish, the genitive form ending in -n is used for both "your" and "yours". Because teidän comes after the verb on (is) rather than right before a noun, it acts just like "yours" does in English.

Who exactly is the "yours" referring to in the word teidän?

Teidän is the possessive form of te, which means "you" (plural or formal). So this sentence means the car belongs to "you all" or to someone you are addressing very politely. If it belonged to just one person informally, it would be sinun instead.

Could I say Tämä on teidän auto instead?

Yes, but the meaning changes slightly. Tämä on teidän auto translates to "This is your car." The word order in the original sentence, Tämä auto on teidän, shifts the focus to translate as "This car is yours." The word order matches English perfectly here!

Do the other personal pronouns use the same -n ending to show ownership?

Yes! Just like te (you plural) becomes teidän, minä (I) becomes minun (my/mine), and sinä (you singular) becomes sinun (your/yours). They all take that genitive -n ending to show who owns something.