An imperfective TAM prefix of the form /r-/ (typically labeled a “Habitual”) is apparent in all branches of the Zapotec language family and can be reconstructed to Proto-Zapotec. Central Zapotec, however, has innovated a progressive prefix /ka(j)-/ (see Broadwell 2015; Smith-Stark 2004). This raises the question: how has the introduction of this progressive impacted the semantics of the general imperfective? Here, I draw together evidence from three modern Central Zapotec languages — including my own research on Tlacochahuaya Zapotec — in comparison with Colonial Valley Zapotec data, to create a fuller picture of the development of these TAM categories.