Päätteensa
Päätteensa is a Finnish suffix that indicates possession by a third person, singular or plural. It is formed by adding the possessive suffix -nsa or -nsä to a noun. The choice between -nsa and -nsa depends on vowel harmony. For example, talo (house) becomes talonsa (his/her/its/their house), and kirja (book) becomes kirjansa (his/her/its/their book).
The päätteensa suffix is used in various grammatical contexts. It can indicate ownership, for instance, in phrases
The use of päätteensa is mandatory when referring to a third-person possessor and the noun is the