kirjoina

Kirjoina is the plural instrumental form of the Finnish noun kirja, meaning “books” in the sense of acting as or being used in the capacity of books. In Finnish, the instrumental case marks function or role, and its plural form is used when referring to multiple items. The singular instrumental of kirja is kirjana, while the plural instrumental is kirjoina.

The form is created by attaching the instrumental plural ending -ina to the stem of kirja, with the usual phonological adjustments that occur in Finnish inflection. This results in kirjoina, the form used for “as books” or “in the capacity of books” when the subject or object is plural.

Usage of kirjoina is primarily found in linguistic descriptions, grammars, and dictionaries illustrating Finnish case forms. It is not a common everyday usage, and in typical speech speakers would often prefer other constructions to express related ideas. Because instrumental plural is a specialized inflection, kirjoina tends to appear mainly in formal or analytic discussions of Finnish grammar rather than in casual prose.

Related forms include kirjana (singular instrumental) and kirjat (nominative plural). Understanding kirjoina helps illustrate how Finnish marks role and function across number in its instrumental case, especially for stems ending in -ja where the stem forms a slightly altered base before the instrumental ending.