Assessing bilingual dominance

This study used two methods to assess bilingual dominance in four groups of 18 Italian–English bilinguals, who were selected on the basis of age of arrival (AOA) in Canada (early: 2–13 years; late: 15–26 years) and percentage use of the first language (L1), Italian (low L1 use: 1–15%; high L1 use: 25–85%). Ratios were derived from the bilinguals' self-ratings of ability to speak and understand Italian compared to English (the “verbal” self-rating ratios) and to read and write Italian compared to English (the “written” self-rating ratios). The ratio of the mean duration of English and Italian sentences produced by each bilingual was also computed. AOA and L1 use had the same effect on the self-rating and sentence duration ratios, which were correlated. The bilinguals who arrived in Canada as young adults and continued to use Italian often were the most likely to be Italian dominant. Dominance in Italian was associated with a relatively high level of performance in Italian (assessed in a translation task) and relatively poor performance in English (assessed by measuring strength of foreign accents). Both groups of late bilinguals (late low, late high) and both groups of early bilinguals (early low, early high) were found to produce English sentences with detectable accents. However, a group of 18 bilinguals (all early bilinguals) selected from the original sample of 72 based on their dominance in English did not have detectable foreign accents. This suggested that interlingual interference effects may not be inevitable.