[Part I. The structure of the lexicon, Morphologically conditioned V-Ø alternation in Hebrew]
I argue in this paper that phonology plays a role in enhancing the distinction among the lexical categories. The argument is based on V alternation in the inflectional paradigms of CVCVC stems which varies in position and type of vowel depending on the lexical category. For example, adjectives exhibit <i>a</i> alternation in the penultimate syllable, while verbs in the final syllable. The Optimality Theoretic analysis reveals that the phonological difference among the lexical categories is minimal (one unique ranking of two constraints for each category), allowing a category distinction without a major increase in the complexity of the phonological system.