Prepositions and the lexical/functional divide: Aphasic evidence

Prepositions occupy a precarious position in syntactic theories which make use of a lexical/functional dichotomy, since they are neither lexical nor functional, at least with regard to existing definitions and criteria. This paper examines data from MC, an aphasic patient who demonstrates an extremely robust dissociation between lexical and functional categories. MC is extremely poor at reading functional categories but his reading of substantives is relatively unimpaired, and he therefore provides a testing ground to help decide whether prepositions are underlyingly represented as lexical or functional. On testing, MC shows that he treats prepositions exactly as if they are functional. Attempts to explain this pattern of performance show that MCʹs deficit cannot be captured along semantic lines, but appears to be syntactic in nature. This leads to a reconsideration of the nature of functional categories: perhaps they are represented in an entirely different way to substantives, perhaps even in a different lexicon (a UG lexicon) which is innately prespecified for syntactic information.