Should we distinguish the instrumental case formed by the affix -(y)n in Old Turkic?
In this paper, we address the issue of distinguishing the instrumental case affix -(y)n and one of the affixes of the accusative case -(y)n (beside -(y)y, and -ny) in Old Turkic languages. We distinguish the instrumental affix -(y)n and the accusative affix -(y)n used in the possessive declension of nouns in Turkic languages since they have different origin.