When does second language learning lead to first language attrition?

Nowhere is the discussion on the relationship between competence and performance more interesting than in the research on bilingualism. Fortuitously, it is in this field of language acquisition and language learning where proponents of both Universal Grammar and Usage-Based approaches have found space for discussion on a number of language contact phenomena. This dialogue parallels a similar coincidence in the study of literacy learning. On this point, a new proposal for research on second language learning and first language attrition appears to fundamentally redefine basic concepts in the field. This response counters that future research will be best served by continuing to apply current conceptions until the discussion of research findings presents a new framework. In addition, a better understanding of language attrition will benefit from an exchange among researchers who work within the framework of different theoretical models. In the end, the exchange will contribute to better understanding the concept of Language Faculty, beginning with an open-ended discussion.