High tone spread in Ekegusii revisited: An optimality theoretic account

Ekegusii, a Kenyan Bantu language, exhibits a complex array of tonal patterns in the finite verbal system including bounded High displacement, bounded High spreading, and unbounded High spreading, each of which is ‘blocked’ from applying in certain configurations. Bickmore (1997) provided a derivational analysis of these facts, but found basic assumptions regarding adjacency and the OCP had to be abandoned to achieve descriptive adequacy. This paper re-analyzes the Ekegusii data within Optimality Theory and eschews the major problems found in the derivational account. It is shown that the surface tonal patterns are the result of a delicate interplay between the productivity of various tonal processes and the avoidance of certain tonal structures. Several theoretical proposals are made in the areas of: 1. (1) constraint sensitivity to lexical strata, 2. (2) tone and accent interaction in OT, 3. (3)bounded spreading as ‘minimal misalignment’, and 4. (4) underspecification of the edge parameter in an ALIGN constraint.