Introduction

This introduction, especially written for this volume, describes aspects of the main topics dealt with in the collection and illustrates shared leading ideas and explanatory analyses – from the insights of the cartographic approach in the analysis of clause structure and its constraints with particular focus on intervention locality, to the resort to acquisition data as a source of inspiration for the control and refinement of theoretical and descriptive hypotheses. It highlights the constant illuminating dialog between theory and experimentation, in particular in the domain of language acquisition, occurring in different modes. Further developments are also mentioned, as well as further considerations in the background and hints to future and ongoing new developments.