The Third Edinburgh Symposium on Historical Phonology
Modern Welsh is similar to many modern Germanic languages such as English, German and Dutch in showing an association between ‘tense’ vowel quality and phonological length. Specifically, long vowels tend to be tense in quality and short vowels tend to be lax, with concomitant alternations. As in the Germanic case, there is some disagreement in the literature on whether quality or quantity (or both) is phonologically relevant in Modern Welsh. In this paper I aim to add to this debate via an overview of the diatopic variation in the relationship between vowel quantity and quality in Welsh and more broadly in the Brythonic languages. I argue that tense/lax quality is likely to be diachronically secondary with respect to quantity, being derivable from prosodic contexts\dash primarily vowel length and syllable structure. One of the notable consequences of this is that even when tense/lax quality has been phonologized (as in, for instance, south-western dialects of Welsh), it is still partly conditioned by quantity and syllable structure; conversely, the distribution of quantity is not significantly determined by vowel quality, which supports the contention that quantity is synchronically active in Welsh phonology.
To support this case for a secondary development of tense/lax quality, I offer a reconstruction of its rise that starts with a tensing of word-final stressed vowels, perhaps initially only restricted to high vowels. This later undergoes rule generalization to embrace both non-high vowels (as in most dialects with tense [e:~oː]) and to syllable-final rather than word-final position (as in South Welsh dialects, where long vowels are allowed in penultimate stressed syllables). I show that intermediate stages of this development are attested across modern Welsh dialects. The secondary nature of the development is supported by the fact that Breton largely shares the quantity system of Welsh, but not the patterning of tense/lax quality.
I argue that the Brythonic languages present an interesting test case for theories that attempt to connect the ‘transphonologization’ of quantity as quality with the rise of vowel shifts: despite the long/short vowels undergoing a tense/lax split, much as in many Germanic languages, the Brythonic system neither became prone to vowel shifting (as in the case of English) nor underwent a further split where the new qualities fit into a new quantity system (as in many North Germanic varieties). I tentatively suggest that this may be due to the closer relationship between tense/lax quality and syllable structure rather than syllable quantity, which is itself related to the fact that Brythonic (and Welsh in particular) experienced less neutralization of vowel quality in unstressed syllables.