Grammatically-conditioned tone lowering in Sandawe

Words in Sandawe may undergo a grammatically-conditioned tone lowering process in which all tones are realised as low tones. Evidence of the underlying tone pattern can be found in the tone of the final vowel, which is low and level if it is an underlying high tone, and low and falling if it is an underlying low tone. The tone lowering process applies to the head in a genitive construction, an adjective in a NP, some conjunctions and, under certain conditions, to a verb. In several contexts, tone lowering minimally contrasts two different grammatical constructions and therefore carries a high functional load in the language.