Cumulative effects in Xitsonga: High-tone spreading and depressor consonants

Depressor consonants in Xitsonga block high-tone spreading. These voiced obstruents and breathy voice consonants do phonetically lower pitch, but phonological blocking of H-tone spreading is not common. This paper reports new findings in which depressors allow H tone to spread into toneless words in Xitsonga, contrary to what we expect if depressor blocking is a categorical phonological phenomenon. This new pattern calls for a reanalysis of the depressor effect in Xitsonga. Building upon an observation that phonological processes can be triggered only if there are multiple triggers (Lionnet 2013), we propose that the depressor effect in Xitsonga is triggered only when a depressor-initial word has an underlying H tone. Unless these two conditions are met (depressor and the presence of H tone), depressor consonants do not block H-tone spreading