ABSTRACT
Language development is not unidirectional, with levels of proficiency and knowledge continually increasing or at least remaining stable: Reverse transfer and lack of exposure and use can, over time, cause changes away from the target system. The increasing interest in these phenomena, which are collectively known as “language attrition,” has led to the realization that bilingual development affects and changes all of the languages represented in the mind, not only the one that is being acquired. This chapter presents an overview of the development of attrition studies as a field and summarizes key insights and questions.
