ABSTRACT
This study shows the value in differentiating synchronic alternations from diachronic sound changes. Though the latter often result in the former, their motivations are often quite different. Formal analyses of one do not necessarily transfer to the other. In this dissertation I have focused on the CL of vowels, which has operated as a sound change in many languages; in a subset of these languages the CL change is still reflected in (often limited) synchronic alternations.
