Instrumentaalkäände

Instrumentaalkäände, often translated as the instrumental case, is a grammatical case found in many languages. It is used to indicate the instrument or means by which an action is performed. For example, in English, the preposition "with" often serves a similar function, as in "He cut the bread with a knife." In languages with a distinct instrumental case, the noun referring to the instrument would be inflected to show its role.

The instrumental case can also denote the agent performing an action in passive constructions, similar to "by" in English passive sentences like "The letter was written by John." Some languages use the instrumental to express accompaniment, meaning "together with" or "along with," though this function can sometimes overlap with other cases or prepositions.

Historically, the instrumental case has roots in Proto-Indo-European, from which many European and Indo-Iranian languages descend. Its presence and specific usage vary significantly across different language families. For instance, it is prominent in Slavic languages like Russian and Polish, and in Finnic languages like Finnish and Estonian. In some languages, the instrumental case may have merged with other cases over time or been replaced by prepositional phrases. The precise grammatical markers and semantic ranges of the instrumental case are defining features of the languages that possess it.