FLB includes FLN combined with at least two other organism-internal systems, which we call ‘sensory-motor’ and ‘conceptual-intentional’ … A key component of FLN is a computational system (narrow syntax) that generates internal representations and maps them into the sensory-motor interface by the phonological system and into the conceptual-intentional interface by the (formal) semantics system … Most, if not all, of FLB is based on mechanisms shared with nonhuman animals … FLN – the computational mechanism of recursion – is recently evolved and unique to our species.

the I-language consists of a computational procedure and a lexicon. The lexicon is a collection of items, each a complex of properties (called ‘features’) … The computational procedure maps an array of lexical choices into a pair of symbolic objects, phonetic form and LF [logical form] … The elements of these symbolic objects can be called ‘phonetic’ and ‘semantic’ features, respectively, but we should bear in mind that all of this is pure syntax and completely internalist.