On the historical source of <i>a ~ u</i> alternations in Dëne Sųłıné optative paradigms

Abstract

In most dialects of Dëne Sųłıné, the optative prefix, reconstructed in Proto Dene as *Gʷə (Krauss 1969), exhibits an alternation in verb paradigms: an a-vowel is found in the 1st and 3rd person singular forms (ɣʷa, wa, or ha, depending on the dialect), while an u-vowel is found elsewhere (ɣʷu, wu, hu). This alternation raises three questions. First, how could the same consonant *Gʷ trigger both raising and lowering of the following vowel? Secondly, what phonological factors conditioned this alternation historically? And finally, does this alternation still belong to the synchronic phonology of modern Dëne Sųłıné dialects?In this paper, I will explore what insights the Contrastivist Hypothesis (CH) (Hall 2007, Dresher 2009) can add to our understanding of this alternation. Representationally, the CH makes it possible to describe lowering to a as spreading of [low], while raising to u involves spreading of [round]. I propose that the choice of which process applied in which forms depended on prosodic factors. In addition, I show what insights the CH can contribute to internal reconstruction. Specifically, I argue that, under the CH, spreading of [low] cannot be a part of the modern synchronic phonology of Dëne Sųłıné, but rather originated at a time before a series of consonant shifts occurred in the language, in particular when the retroflex series was still part of the consonant inventory.