Realis morphology and Chatino’s role in the diversification of Zapotec languages

Abstract This paper concerns a semantic change whereby a continuous aspect prefix was reinterpreted as marking realis mood. This change took place in Chatino and then diffused to the Southern Zapotec subgroup, contributing to the genetic diversification of the Zapotec languages. Proto-Zapotecan marked irrealis mood with *k- and did not mark realis. *n- indicated continuous aspect and could concatenate with perfective *ku- to render a resultative reading. A continuous-marked positional verb *n-te later grammaticalized as a progressive prefix in Chatino. As both perfective and progressive refer to (at least partially) realized situations, *n- was reanalyzed as a marker of realis mood that could concatenate with aspectual viewpoint prefixes. The realis prefix is shown to be one of several traits diffused from Chatino which contribute to the creation of the Southern Zapotec clade and its divergence from Monte Albán Zapotec.