Categorizing heads, aka categorizers, like n and v are the elements that make nouns and verbs in approaches embracing syntactic decomposition. In this paper they are claimed to bear distinctive LF-interpretable categorial features [N] and [V], features that set the interpretive perspective of nouns and verbs as sortal and extending-into-time respectively. Consequently, I argue that categorizers are necessary for the interpretation of roots because they provide the interpretive perspective in which concepts can be related with semantically deficient roots through syntax. This explains the observation that free roots cannot be merged directly in a syntactic derivation. On the basis of their categorial status, the paper also offers a new classification of the basic elements syntax manipulates, which includes roots, inner morphemes, categorizers, and functional heads.
©Walter de Gruyter