Aikuisiin

Aikuisiin is a Finnish grammatical form derived from the noun aikuinen, meaning adult. It is the illative plural of that noun, used to indicate movement toward, or entry into, the group of adults, or to mark a discourse focus aimed at adults. In Finnish, the illative case expresses direction of motion or transition into a state, and its plural form for aikuinen is aikuisiin. The singular illative is aikuiseen, while the plural illative is aikuisiin. The illative is one of several cases used to express location, direction, or target in Finnish, and it often signals a shift in focus or scope rather than a concrete place.

Usage of aikuisiin tends to appear in more formal or descriptive contexts, such as linguistic analyses, policy discussions, or texts that address adult audiences or groups. In everyday language, speakers more commonly use alternative constructions depending on the intended nuance, such as forms that mark the target group with other cases or prepositional phrases. The choice between illative and other cases depends on the verb and the syntactic role the noun plays in the sentence.

Etymology and morphology: aikuinen forms the base noun meaning “adult.” The illative plural suffix -iin attaches to the stem to yield aikuisiin. This pattern aligns with Finnish noun declension rules for illative forms, illustrating how case endings convey directional or transitional meaning in relation to number. See also Finnish illative case, Finnish noun declension, and aikuinen.