Bilingualism: Language and Cognition

First clues to the existence of two input languages: Pragmatic and lexical differentiation in a bilingual child 1

a1 Lesley College


While it is now commonly accepted that simultaneous bilingual children can differentiate their two languages from very early in development, it is still not very well understood how they come to understand that there are two languages in their input. The purpose of this study was to examine how a bilingual child might come to an understanding of the existence of two languages in terms of pragmatic differentiation (use of the appropriate language for the context) and lexical differentiation (use of translation equivalents). Using data from a Portuguese-English bilingual child from 1;0 to 1;6, this study showed that the child showed evidence of pragmatic differentiation before lexical differentiation. If these results are replicated, they suggest that bilingual children's understanding of the appropriate social use of their two languages may lead to an understanding that the translation equivalents in their vocabulary belong to two distinct input languages.

(Received December 30 1997)
(Revision accepted March 6 1998)

c1 119 Yorktown Street, Somerville MA 02144, USA E-mail:


1 I thank the family who participated in this study for their enthusiastic and long-term participation. I thank Giovanni Secco for his collaboration in collecting, transcribing and checking the reliability of the data and Chris Westbury for his feedback on an earlier version of this article. Feedback from three anonymous reviewers was helpful in revising the presentation of this study. Lastly, I thank Catherine Snow and the Harvard Graduate School of Education for welcoming me as a visiting scholar for the year in which this study was done.