Synchrony, diachrony and Lexical Phonology: the Scottish Vowel Length Rule

Introduction

A typically English dialect is one which preserves a reflex of the West Germanic system of phonemic vowel length, having one set of lexically short and one of lexically long stressed vowel phonemes ... Scots dialects, on the other hand, are characterized by the disruption of this dichotomous pattern, resulting in the loss of phonemic length: vowel duration is to a large extent conditioned by the phonetic environment. (Harris 1985: 14)

The process generally credited with this disruption of `normal' English quantity patterns, both diachronically and synchronically, is the Scottish Vowel Length Rule. SVLR was first formulated in 1962 by A.J. Aitken (after whom it is also known as Aitken's Law), although its effects had been noted much earlier in dialect studies such as Patterson (1860; Belfast), Murray (1873; Southern Scots), Grant (1912), Watson (1923; Roxburghshire), Dieth (1932; Buchan), Wettstein (1942; Berwickshire) and Zai (1942; Morebattle). We shall use the history and the synchronic status of SVLR and related processes as a test case of the way Lexical Phonology can model the development of a synchronic rule from its historical antecedent. This will essentially involve describing Scottish varieties in their own terms, however, we shall compare the resulting system(s) with those developed above for RP and GenAm, raising the issues of dialect differentiation and variation. RP and GenAm have proved to be extremely closely related, and it is clear that these varieties have simply not diverged far enough, or for long enough, to provide us with conclusive evidence on the nature, extent and cause of underlying dialect divergence. First, however, we require an outline of the linguistic situation in Scotland, and of its origins.