Grammatical versus lexical words in theory and aphasia: Integrating linguistics and neurolinguistics
The distinction between grammatical and lexical words is standardly dealt with in terms of a semantic distinction between function and content words or in terms of distributional distinctions between closed and open classes. This paper argues that such distinctions fall short in several respects, and that the grammar-lexicon distinction applies even within the same word class. The argument is based on a recent functional and usage-based theory of the grammar-lexicon distinction (Boye & Harder 2012) and on the assumption that aphasic speech data represent the ideal testing ground for theories and claims about this contrast. A theoretically-based distinction between grammatical and lexical instances of Dutch modal verb forms and the verb form hebben was confronted with agrammatic and fluent aphasic speech. A dissociation between the two aphasia types was predicted and confirmed.