Synchronic stratum-specific rates of application reflect diachronic change:
 morphosyntactic conditioning of variation in English /l/-darkening

Abstract

Phonological processes that exhibit morphosyntactic sensitivity can provide evidence of historical processes which have ascended through the grammar over time. English /l/-darkening shows such effects. Although syllable-based accounts state that light [l] occurs in onsets (e.g. light) and dark [ɫ] in codas (e.g. dull), several studies report overapplication of darkening to onset /l/ in certain morphosyntactically defined positions: e.g. word-finally in phrases such as heal it, and stem-finally before a suffix in words such as heal-ing. Although many phonological theories attempt to account for such opacity, they cannot adequately account for the potential variability in application alongside this. The present paper explores these ideas through modelling data on /l/- darkening in English taken from Hayes’s (2000) Optimality Theoretic study. It is argued that a combined Stochastic Stratal OT approach to the data is an improvement over a parallel stochastic model (e.g. Boersma & Hayes 2001) because it avoids fixed innate constraint rankings, which are required to prevent the prediction of impossible grammars. Moreover, it is shown that observations about the diachronic life cycle of phonological processes enable us to deduce quantitative predictions about rates: should apply with lower frequency in smaller morphosyntactic domains.