LAUSR

All modern Basque dialects have at least 5 contrastive vowels /i, e, a, o, u/. One Basque dialect, Zuberoan, has developed a contrastive sixth vowel, the front rounded high vowel /y/. This development is arguably due to sustained contact with neighboring Gallo-Romance languages. This paper supports empirically the historical development of the /u/ vs. /y/contrast and provides a detailed analysis of the contexts that inhibited the /u/ > /y/sound change. Fronting was inhibited when the vowel was followed by an apical sibilant, a tap /r/or an rT cluster (where r is a rhotic, and T an alveolar obstruent), arguably due to coarticulatory effects. Fronting occurred when /s./, /r/ or non-coronal rhotic-obstruent clusters followed /u/. Zuberoan /u/-fronting illustrates the importance of language contact and phonetics in the phonological analysis of historical developments.