On the nature of roots

Abstract This paper offers a review of a current understanding of the content and the form of linguistic roots. It first updates and buttresses the case against semantic content of uncategorised roots and for Late Insertion of roots; then it investigates how native speakers identify roots. More specifically, the idea that roots may be polysemous or may encode the shadow of a denotation, namely the common denominator of the denotations of words derived from it, is refuted on the basis of conceptual and empirical arguments from a number of languages. Subsequently, the existence of a spectrum of content to which roots belong, with roots ranging from contentless to semantically specific and concrete, is also shown to be illusory, and to result from the actual productivity, hence diversity, of the words derived from it. Arguments for Late Insertion of roots are then reviewed and updated, divorcing roots from the forms that realise them. These arguments are systematically combined with the semantic contentlessness of roots in support of Acquaviva’s analysis of them as abstract indices, i.e. as the syntax-internal criteria of lexical identity. This account is taken to its logical conclusion in the final section: if roots are indeed abstract indices, then they cannot be identified either by the semantic content they realise within grammatical structures or by their forms. An account is therefore advanced according to which roots are identified just once by native speakers over their lexicon at a given moment and on the basis of three heuristic principles: one form-based, one based on the feature content and the exponence of the structures in which roots are embedded, and one taking care of root suppletion.