Language organization and language change in bilinguals

Two experimental studies with bilingual speakers examined the influence of (I) semantic organization across language, (2) input language change and (3) output language change on speech encoding during a sentence completion task. The first study used fluent Welsh-English bilinguals while the second used fluent French-English bilinguals; all subjects were at school in the U.K. A model proposed how subjects with different degree of overlap in bilingual semantic organization achieved functional separation of the two languages. Predictions derived from this were tested and were substantially confirmed for both groups of bilinguals. It was concluded that subjects have different degrees of overlap in semantic organization of their two languages and that this influences speech encoding where input or output language changes are present.