The document discusses the evolution of syntactic theories and their implications for second language (L2) acquisition research, particularly focusing on generative grammar and the strong Universal Grammar (UG) hypothesis. It highlights various studies that explore the role of first language (L1) transfer and the poverty of stimulus in L2 acquisition, emphasizing the need to consider broader theoretical revisions in linguistic research. The authors advocate for comparative interlanguage development as a method to better understand L1 influence and transfer in L2 learning.