High tone bumping in Runyankore

Abstract In this study I present the unusual properties of a rule of High Tone Bumping (HTB) which occurs in certain languages of the Rutara subgroup of Bantu. By this process, the final H tone of a word or clitic “bumps” a preceding H tone one syllable to the left, e.g. /kaawá=kí/ → kááwa=kí ‘what coffee?’ (as realized utterance-medially). The triggers consist of /H/ CV monosyllables as well as VCV words whose final syllable is /H/. Since these can interact with each other, frequently with V+V vowel coalescence, this produces H tone sequences of trigger-targets in which each H appears to be bumped one syllable to the left. I present the facts of HTB in some detail and offer two synchronic analyses, one involving a left-to-right iterative rule, the other recognizing H*-marked tone spans that can be globally accessed to apply HTB all at once. I conclude by considering possible historical origins of HTB.