Abstract
This paper investigates lexical mass-to-count and count-to-mass operators in Slavic languages, primarily Russian and Ukrainian, by exploring the distribution and semantic contribution of the suffix -_in_/-_yn_. The focus is on two uses of the suffix: the singulative turns mass nouns like _gorox_ ‘pea’ into count, denoting sets of natural units (e.g., _gorošina_ ‘a pea’), and the massifier applies to count nouns, such as _kon’_ ‘horse’, and turns them into mass (e.g., _konina_ ‘horsemeat’). It is proposed that each use of -_in_/-_yn_ contributes a partition operator which triggers a new division into units of the original material part. It is further argued that the singulative and the massifier should be unified, given their (i) phonological identity, (ii) shared grammatical properties, and (iii) common semantic core. Under the proposed analysis, there is a single suffix that functions as an underspecified lexical partition shifter.