I show a way to solve Borer’s (2013) “puzzle of the adjective”: adjectives behave like derived words regarding some morphological phenomena and like roots regarding others. My key overarching assumption is that adjectives are in fact non-primitive, comprising an adposition and a nominal. Other assumptions, framed within a syntactic approach to morphology, include: a universal recursive hierarchy of lexical categories; the idea that categorizers are simple lexical items relating a span of the categorial hierarchy to an exponent; the assumption that lexically and morphologically conditioned allomorphy is sensitive to stretches of the syntactic representation, rather than to exponents; and a rather flexible lexicalization procedure, one syntactic representation being mappable to different combinations of lexical items
