The Nasal in Dagbani Prosody

Abstract

This paper presents a study on nasality in Dagbani, focusing on the unique contribution of nasals to the understanding of Dagbani prosody. While much is known about nasality from previous studies, the implication of their behaviour to the structure of Dagbani prosody has not been fully explored. Nasals provide crucial evidence for aspects of Dagbani prosody that would otherwise remain less understood, four of which are noted in this talk.

First, coda nasals bear tone and segmental length, which are key in establishing the mora as the tone-bearing unit in Dagbani. Second, the phonological behaviour of nasals is required for a fuller understanding of the syllable types permitted in Dagbani. Nasals are the only coda consonants that license vowel lengthening. In an underlying CVC syllable, vowel lengthening requires the nasalisation of an oral coda consonant. Nasals also provide the only examples of ambisyllabic segments in Dagbani.

Third, nasalisation is the only process meant solely to satisfy a prosodic requirement. When oral consonants are nasalised, the goal is to realise a nasal in the coda. When other phonological processes affecting consonants take place, the surface form does not have any implication on the prosody.

Finally, syllable structure processes are triggered or avoided on condition that the surface form is a syllabic nasal or a nasal coda. Insertion, for instance, is triggered in many contexts to avoid a consonant cluster, unless the second of the cluster is a nasal, in which case it becomes the nucleus of the syllable. This is in spite of both syllabic consonants and codas being marked. The typological implications of these observations are discussed