explores the difference between words however defined and structures however constructed. It sets out to demonstrate over three volumes that the explanation of linguistic competence should be shifted from lexical entry to syntactic structure, from memory of words to manipulation of rules. Its reformulation of how grammar and lexicon interact has profound implications for linguistic, philosophical, and psychological theories about human mind and language. Hagit Borer departs from language specific constructional approaches and from lexicalist approaches to argue that universal hierarchical structures determine interpretation, and that language variation emerges from the morphological and phonological properties of inflectional material.

, the third and final volume of , applies this radical approach to the construction of complex words. Integrating research in syntax and morphology, the author develops a new model of word formation, arguing that on the one hand the basic building blocks of language are rigid semantic and syntactic functions, while on the other hand they are roots, which in themselves are but packets of phonological information, and are devoid of both meaning and grammatical properties of any kind. Within such a model, syntactic category, syntactic selection and argument structure are all mediated through syntactic structures projected from rigid functions, or alternatively, constructed through general combinatorial principles of syntax, such as Chomsky's Merge. The meaning of 'words', in turn, does not involve the existence of lexemes, but rather the matching of a well-defined and phonologically articulated syntactic domain with conceptual Content, itself outside the domain of language as such. In a departure from most current models of syntax but in line with many philosophical traditions, then, the Exo-Skeletal model partitions 'meaning' into formal functions, on the one hand, and Content, on the other hand. While the former are read off syntactico-semantic structures as is usually assumed, Content is crucially read off syntactico-phonological structures.