Yiddish possessives as a case for genitive case

Yiddish is standardly characterised as a language with a three-case system, differentiating between nominative, accusative and dative. Possessor noun phrases that occur before the possessum appear to be marked by dative and an additional formative ‑s, which attaches to the head noun at the right edge of the possessor phrase. This article presents evidence for considering the possessive marker part of the exponence of genitive case, and thus, for revising the description of the Yiddish case system. The arguments given concern, on the one hand, the morphosyntactic status of the possessive marker and, on the other, the fact that, upon closer inspection, the nominal with which the possessive marker is combined is not identical with a noun phrase case-marked for dative.