Unpacking portmanteaux: Non-linear morphology in the Ebira STAMP system

This paper investigates linear and non-linear morphology in verbal inflection in Ebira, a Benue-Congo language of Nigeria. Non-linear morphology does not appear on the root, but rather occurs within pre-verbal units called STAMP markers or STAMP portmanteaux, a mnemonic for subject agreement, tense, aspect, mood, and polarity. Based on the previous description of Ebira morphosyntax, this paper decomposes its STAMP markers into several sub-STAMP morphs. Specifically, inflectional categories for subject agreement (1S, 2, 3S, 1P, 3P), aspect/mood (HABITUAL, COMPLETIVE, SUBJUNCTIVE, CONTINUOUS, PERFECT), polarity (NEGATIVE), and clause-level meanings (INTERROGATIVE, 'IF', 'WHEN') are decomposed into various floating tones, floating moras, and unassociated segments. By decomposing STAMPs in this way, it makes testable predictions for future Ebira studies, as not all logically possible category combinations have been investigated yet. This paper concludes by discussing the areality of STAMP markers in West and Central Africa (the so-called Macro-Sudan Belt), which is complicated by analytic vs. synthetic transcription practices by linguists. In order to circumvent issues of transcription, I propose that the areality of STAMP markers in Africa be based on whether the individual STAMP categories form a constituent before and to the exclusion of the verb root, requiring explicit evidence independent from transcription practices.