Sequences of high tones across word boundaries in Tswana

The article analyses violations of the Obligatory Contour Principle (OCP) above word level in Tswana, a Southern Bantu language, by investigating realization adjacent lexical high tones across boundaries. results show that boundaries downstep (i.e. lowering second series tones) only takes place within phonological phrase. A phrase break blocks downstep, even when necessary tonal configuration is met. phrase-based account adopted order to for occurrence downstep. Our study confirms pattern previously reported closely related language Sotho and provides controlled, empirical data from based on read speech twelve speakers which has been analysed auditorily two annotators as well acoustically.