Suzanne Flynn and Wayne O'Neil Massachusetts Institute of Technology I. INTRODUCTION The theory of Universal Grammar (UG) as explicated e. g. in Chomsky, 1986, has led to explosive developments in the study of natural language as well as to significant advances in the study of first language (L I) acquisition. Most recently. the theory of UG has led to important theore tical and empirical advances in the field of adult second language (L2) acquisition as well. The principle impetus for this development can be traced to the work in linguistics which shifted the study "from behavior or the...

Recent developments in linguistic theory have led to an important reorientation of research in related fields of linguistic inquiry as well as in linguistics itself. The developments I have in mind, viewed from the point of view of government-binding theory, have to do with the character ization of Universal Grammar (UG) as a set of subtheories, each with its set of central principles (perhaps just one principle central to each subtheory) and parameters (perhaps just one for each principle) according to which a principle can vary between an unmarked ('-') and a marked ('+') para metric value...

Suzanne Flynn and Wayne O'Neil Massachusetts Institute of Technology I. INTRODUCTION The theory of Universal Grammar (UG) as explicated e. g. in Chomsky, 1986, has led to explosive developments in the study of natural language as well as to significant advances in the study of first language (L I) acquisition. Most recently. the theory of UG has led to important theore tical and empirical advances in the field of adult second language (L2) acquisition as well. The principle impetus for this development can be traced to the work in linguistics which shifted the study "from behavior or the...