The characteristic ending for indicating external possession
is -é.
Kinek
a kutyája? Whose dog (is it)?
Ágié. (It's) Agi's.
TODO - Miklos's hat example
Just like with explicit possession of multiple objects,
we have -i-
Kinek
a kutyái? Whose dogs (are these)?
Ágiéi. (They're) Agi's.
TODO - Miklos's hat example