sellaisiin

Sellaisiin is a Finnish illative plural form of the demonstrative adjective sellainen, meaning such or that kind of. It is used to refer to multiple items or people that belong to the same kind or category as something already mentioned or implied. As a case form, sellaisiin functions as a determiner or pronoun that introduces a following noun in the illative plural, indicating direction or movement into a group or set of things.

Morphology and usage: The base is sellainen. When declined for number and case, the illative plural ending is -iin, yielding sellaisiin. This form appears with nouns in illative plural, for example sellaisiin taloihin (“into such houses”) or sellaisiin asioihin (“into such matters”). Sellaisiin is thus not a standalone noun but a case-inflected determiner, used to specify a class of items being spoken about.

Nuance and register: Sellaisiin is common in written and formal Finnish, but it also appears in everyday speech when the speaker wants to generalize about a category rather than naming each specific item. It contrasts with related forms such as sellaiset (nominative plural “such ones”) and sellaisia (partitive plural “such … [some]”).

Examples:

- En halua sekaantua sellaisiin asioihin.

- Hän viittasi sellaisiin taloihin, joissa turvallisuus on varmistettu.

See also: sellainen, sellaiset, sellaisia. The form demonstrates how Finnish adjectives agree with the noun they modify in case and number, shaping meaning through the illative mood.