vuoristoisten

Vuoristoisten is a Finnish inflected form of the adjective vuoristoinen, meaning mountainous. It functions as the genitive plural form of the adjective, used when describing a noun in the genitive plural. In practice, vuoristoisten appears in phrases such as vuoristoisten alueiden or vuoristoisten ihmisten, where it modifies a following noun in the genitive plural.

In Finnish grammar, adjectives agree with the nouns they describe in case and number. For adjectives of the -inen class, the genitive plural ending is typically -isten, yielding forms like vuoristoisten. The form is not a standalone noun; rather, it marks a quality—mountainousness—belonging to or characteristic of a plural noun phrase. Common contexts include geography, ethnography, and regional description.

Usage examples illustrate its function. Vuoristoisten alueiden luonto on karua mutta monipuolista means the nature of the mountainous regions is austere yet diverse. Vuoristoisten ihmisten tarinat offer stories of the mountain peoples. Vuoristoisten asukkaiden kieli sekä kulttuuriperintö ovat tärkeä osa alueen identiteettiä. These examples show how vuoristoisten collaborates with nouns in the genitive plural to convey possession or association.

Origin and related forms: vuoristoinen denotes “mountainous,” while vuoristoisten is the genitive plural form used with genitive nouns. This pattern is common in descriptive Finnish, especially in geographic or ethnographic writing.

See also: Finnish grammar, adjectives, genitive case, geographie descriptive terms.