This talk presents data from Estonian, Serbian, Finnish, Saami and Ossetic concerning the marking of the genitive case, the partitive case and the plural. The data suggest that there is a linear contiguity constraint on syncretism such that the genitive and the plural cannot be syncretic unless the partitive is the same as well. I explain this using Borer’s idea about the organisation of the DP (mass-count-plural), and the Nanosyntax model of spellout.