This research aimed to disentangle the effects of bilingualism and language-learning difficulties by establishing profiles for early vocabulary production in children exposed to more than one language across different contexts. We also wanted to identify the factors that might place some children at risk for language impairment.
250 young bilinguals exposed to six language pairs (Maltese and English, Irish and English, Polish and English, Turkish and German, French and Portuguese, and English and Hebrew) were tested using adaptations of the MacArthur Bates Communicative Development Inventories: Words and Sentences (Fenson et al., 2007). The children were aged 24-36 months and their expressive vocabulary in both languages was measured. In addition, a specially designed background questionnaire was used to gather information on developmental, demographic and language exposure variables.
The results showed a wide range in vocabulary development which could be somewhat attributed to SES as measured by maternal education and how often the children were exposed to the second language. Lower vocabulary scores were also associated with a lack of word combinations at two-years. We also looked at those children performing below the 10th percentile to determine what factors were related to their relative delay. Most of this group came from the Polish-English speakers, recent immigrants to the UK and Ireland, and the parents had high levels of education but low occupations.
A feature of the entire group of lower-performing children were lower levels of parental education overall, parental concerns about language development, no two-word combinations at 2-years and family history of speech and language difficulties.
This study has implications for the factors that might help to identify bilingual children at risk for language impairment as well as the language enrichment that might be needed for young bilinguals.