The Cross-Lingual Dimensions of Language Proficiency: Implications for Bilingual Education and the Optimal Age Issue

Abstract

It is argued that a dimension of cognitive/academic language proficiency (CALP) can be empirically distinguished from interpersonal communicative skills such as accent and oral fluency in both Li and L2, and that cognitive/ academic proficiencies in both L1 and L2 are manifestations of the same underlying dimension. This analysis of language proficiency and its crosslingual dimensions is applied to the interpretation of data on the effects of bilingual education programs and on the age issue in second language learning.