Andrew Miles Byrd

Alongside the expected reflexes of the Proto-Indo-European causative suffix * -éi̯e/o- , there appears in Indo-Iranian a second, expanded version that contains a labial consonant: Indic -(ā)páya- and Eastern Iranian (EIr.) *-(ā)u̯ai̯a- , the latter continued in Khotanese -ev- , Khwarazmian -(’)wy- , and other modern EIr. languages. In this paper, we will argue that *-(ā)u̯ai̯a- is also the source of a causative marker in two closely related Caspian (Western Iranian) languages, Gilaki and Tati-Talyshi, through a reconstructable Proto-Caspian form *-āwēn- . We propose that these three suffixes, -(ā)páya- , *-(ā)u̯ai̯a- , and *-āwēn- , originated in Proto-Indo-Iranian, through the rounding of a root-final laryngeal to a labial sound in causative formations.