Tonal aberrations signaling contact-induced grammatical change.

We examine tonal and non-tonal features involved in the diachronic emergence of a future tense category in Emai, an Edoid language of southern Nigeria. The extant tense system in Emai incorporates values for both temporal distance and the temporal units past, present, and future. We concentrate on linguistic coding of the future and its associated expressions. Initially, we review the set of markers for futurity in the West Benue Congo branch of Benue Congo, including the Edoid languages. Forms in neither align with Emai future coding, which is conveyed by tonal and segmental co-exponents. The Emai future pattern is consistent with the coding of present tense, although not past, which relies exclusively on tone. Moreover, the future does not exhibit tonal polarity reflective of temporal distance (proximal/distal); its proximal form does not correlate with a distinct temporal adverb; and the negative future, unlike past and present, corresponds to temporal interpretations that neutralize temporal distance rather than tense. To account for these restrictions, we propose that future is a relatively recent addition to the tense profile in Emai and that its segmental exponent emerged from contact-induced grammaticalization realized under multi-generational and asymmetrical bilingualism with Yoruba. Under this circumstance a combination of grammaticalization and tonal reanalysis allowed Emai future lɔ́ with high tone to emerge from Yoruba deictic motion verb lɔ 'go, move away from deictic center' with mid tone. [ABSTRACT FROM AUTHOR]