This article provides a description and an Optimality Theory (OT) analysis of contact-induced changes and variation in contemporary Yoruba syllable structure. The article claims that a major diachronic change has occurred in the syllable structure of Yoruba phonology due to its continued contact with English, resulting in the invention, preservation, and hypercorrection of clusters and codas. I characterize this change in terms of OT constraint re-ranking (Miglio and Moren 2003) and assess the resulting synchronic variation against the indexed constraint approach of Itô and Mester (1995a, b, 1999), the ranked-winners approach of Coetzee (2004), the partial-order co-phonology of Anttila (1997), and the Maximum Entropy (MaxEnt) model of Goldwater and Johnson (2003). I show that none of these approaches is able to account independently for the categorical, gradient, and lexically conditioned variation that characterize the contemporary Yoruba syllable structure, but rather that a MaxEnt model augmented with lexical indexation is the most economical model that fits the Yoruba data accurately.
