This paper presents data bearing on two key issues in morphophonological theory: 1) the
domain of phonological evaluation, and 2) the item-versus process-morphology debate. I
present data from Guébie (Kru)[Côte d'Ivoire] showing that imperfective aspect is exponed
by a scalar shift in surface tone, which can affect either the tone of the inflected verb, or the
subject noun phrase. There are four tone heights in Guébie, and the first syllable of a verb
can underlyingly be associated with any of the four tones. In imperfective contexts only, that …