Phonetics pushing syntax: S/Aux fusion and the rise of subject cross-reference in Mande

This paper investigates how the fusion between subje ct person markers and auxiliaries is related to the rise of subject cross-reference, based on a sample of 28 Mande languages (Niger-Congo, West Africa). Building my microtypology on two independent parameters, i.e. S/Aux fusion and subject cross-reference, I demonstrate that the distribution of language types reveals an implicational relationship between the two parameters in Mande: no S/Aux fusion implies no subject crossreference, and subject cross-reference implies S/Aux fusion. This distribution suggests that S/Aux fusion may trigger the rise of subject cross-reference. To account for this, I argue that in constructions with strong S/Aux fusion and no subject cross-reference, non-fused predicative markers are replaced by fused personpredicative markers within the same syntactic slot, i.e. Aux. This process is driven by low textual frequency of non-fused predicative markers and strong phonetic erosion of predicative markers within person-predicative forms.