In linguistics, the instrumental case indicates that a noun is the instrument or means by which the subject achieves or accomplishes an action. The noun may be either a physical object or an abstract concept.
For example, in this Latin sentence:
- librum stylo scripsi.
the inflection of the noun indicates its instrumental role -- the nominative stylus changes to the ablative stylo. English, lacking an instrumental case, might use a preposition (usually with) to express the same meaning:
- I wrote the book with a pen.
The instrumental case appears in Old English, Sanskrit, and the Balto-Slavic languages. An instrumental/comitative case is arguably present in Turkish and other Altaic languages.
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