ABSTRACT
The field of language acquisition has made remarkable progress in recent years. There is no area of cognitive science that has advanced at a quicker pace. The field is full of reliable and nonobvious generalizations, relations to other fields are understood, a good deal about the relation between normal and impaired development is understood, and the relative contributions of learning and development have begun to be sorted out in a coherent manner. This chapter sketches out some of these results and attempts to give an overall view of the central questions and the answers that current research suggests. For the domain of phenomena I will pick one important case, the development of central properties of sentence structure. I have sacrificed breadth of coverage in phenomena and precision of technical development in order to have space to discuss the central questions and to make the results available to nonspecialists. A major purpose of this chapter is to show how important discoveries concerning impaired linguistic development (SLI), one of the foci of this book, flow naturally from and contribute to the advances in the study of normal language acquisition.
