The crucial changes that generative linguistics has suffered along the last years involve the increasing of underlying leading ideas about the object of linguistics as well as modifications in the form and organization of the grammar. This paper concerns both questions just mentioned. In the first part an informal and philosophical-like presentation of the set of new distinctions made by this linguistics is given. The distinction core vs periphery, derivational vs representational and sentence vs discourse grammar are discussed and briefly illustrated. The notions of parametric variation and modularity are also explained. In the second part the interplay between sentence and discourse grammar is specifically illustrated and analyzed. It is shown, first, that certain rules of discourse have to apply at the level of "logical form" and after other deletion rules apparently similar but belonging to sentence grammar. Secondly, a correlation between structural properties and the discourse phenomenon of topic-comment is shown.