Lexicalisation of tonal downstep in Yoruba

Abstract This work challenges the assumption that tonal downstep is a juncture feature in Yoruba by providing data, both from everyday conversation and from classical Yoruba dictionaries, which prove that the phenomenon is part of the lexical composition of many Yoruba words. It is further argued that the derivational path of some of the words having downstep has already been lost. It is also reported that the Assimilated Low Tone phenomenon, which is an indication that the delinked Low tone triggering downstep is still active in the phonology, is currently being lost in many dialects, which is giving way to more classical-like downstep in the language. Cross- dialectal evidence from Oyo, Ibadan, Onko, and Ijebu dialects, as well as from pitch tracks are provided to support the arguments and it is suggested that Yoruba is developing downstep via Assimilated Low Tone, and that this process has now reached an advanced stage.