aikuiseen

Aikuiseen is the illative singular form of the Finnish noun aikuisen/aikuinen, meaning adult. It functions as the form used for indicating movement toward or into the state or realm of being an adult, typically in constructions where the illative case marks direction or transition.

In usage, aikuiseen appears most often when the noun aikuinen modifies another noun or appears in phrases that describe entering an adult-related environment or phase. Common examples include aikuiseen elämään, meaning into adult life, and aikuiseen maailmaan, meaning into the adult world. In these expressions, aikuiseen supplies the illative meaning to the second element, such as elämä or maailma, rather than standing alone.

Grammatical notes: aikuiseen, as the illative form, follows Finnish illative patterns for a masculine- or living-being noun, and it is primarily seen in more formal, literary, or descriptive contexts. When discussing becoming an adult, Finnish typically uses other constructions such as tulemaan aikuiseksi (to become an adult) or aikuisuuteen (into adulthood), where translative or inessive/illative forms of related words appear.

Related terms include aikuisuus (adulthood) and aikuisistuminen (the process of growing to adulthood). The illative form aikuiseen is thus a specialized inflection used in phrases that express movement toward or into the domain of adulthood, rather than a standalone predicate.

See also: Finnish illative case, aikuisuus, aikuisistuminen, aikuiseksi.