The unbounded nature of our linguistic capacities has inspired the computational approach to language: knowledge of the mother tongue implies implicit mastery of a system of recursive procedures, capable of generating a potentially unlimited set of sentences. More than half a century of discussion on the nature of recursion in natural languages has led to the postulation of an extremely simple recursive procedure, "Merge", which combines two syntactic objects into a third, hierarchically superordinate object. The hypothesis that Merge is the basis of syntactic Combinatorics implies the strongly hierarchical character of linguistic expressions. The first part of the talk is devoted to presenting the structure-building system based on "Merge", illustrating certain hierarchical effects (locality on movement, morphosyntactic and interpretative phenomena linked to hierarchy), and criticizing alternatives based on a purely linear organization of sentences.
The second part deals with the mapping of syntactic structures. Syntactic structures are complex objects, depending on the recursive nature of "Merge" and the richness of the functional lexicon; for some fifteen years now, mapping studies have been attempting to draw systematic maps of the different zones of the syntactic tree, thus providing a new tool for theoretical studies and syntactic comparison. Cartographic studies discover, among other things, stable functional sequences across languages in different regions of the syntactic tree. In the last part of the presentation, I would like to discuss lines of research that attempt to give a "further explanation" to functional sequences, trying to bring their properties back to the fundamental principles governing linguistic computations (locality, etc.).
