An Optimality Theoretic Perspective on Perfective Imbrication in siSwati
Imbrication is a morphophonological change in many Bantu languages in which a morpheme -il-/-ir-, which may be glossed as perfective, stative or past (Hyman 1995), fuses with the verb stem through CV metathesis, consonant deletion and vowel coalescence, subject to varying requirements and degrees of productivity (Bastin 1983). This paper examines imbrication of the perfective suffix -il- in siSwati from the perspective of Optimality Theory (McCarthy and Prince 1996, Prince and Smolensky 2004), in which the realisations of input forms are selected through competing requirements of faithfulness to input forms and elimination of marked configurations. Drawing on Kayne’s (1995) theory of the antisymmetry of syntax, it is proposed that the perfective suffix in siSwati is right-adjoined to the verb stem, in violation of this theory. Recasting the prohibition against right adjunction as a violable Optimality- Theoretic constraint, metathesis is motivated as a strategy to conceal the violation by fusing morphemes at the adjunction site.