1. Introduction
A first language can occasionally come into disuse (undergo attrition) during childhood. Some longitudinal studies in children have documented the process of attrition over several weeks or months. Nicoladis and Grabois (2002) studied the simultaneous loss of Cantonese and acquisition of English in a young Chinese girl adopted by an English-speaking family in Canada, at 17 months of age. The interactions with native Cantonese speakers over the 3 months following the child's arrival in Canada, revealed a rapid loss in both production and