Preverbal a-marking in Palenquero Creole

Formally similar grammatical features in a creole and its genetic or areal relatives may indicate substrate transfer, lexifier influence, or grammaticalization. Against this backdrop, the present study investigates the origin(s) of the preverbal past marker a in Palenquero Creole (Colombia). Results from distributional analysis and tests for significance indicate that several diachronically-related meanings are a-marked at rates approaching obligatory, suggesting advanced grammaticalization. Comparative results for Peninsular haber + PP suggest that past marking has grammaticalized much further in half the time in Palenquero Creole than in its lexifier, Spanish. Why? I argue, against traditional accounts about the origins of a, that, given the contact history of Palenquero speakers, most likely a pre-existing Kikongo prefixal form merged with an already grammaticalizing haber, thus propelling grammaticalization in the creole. The synchronic patterning shows adherence to typological patterns observed for perfectives in line with well-known constraints on competition and selection in contact languages, such as their grammatical congruence or particular social ecologies.