Irish is now a threatened
minority language in Ireland which is generally acquired in a bilingual context
with English and shows significant influence from English. For this reason, the
adaptation of the MacArthur- Bates Communicative Development Inventories to Irish
involved developing a single bilingual test in order to produce the most
accurate and sensitive profile of children’s acquisition of Irish and English. Here
we report on how children aged 17-36 months acquired vocabulary, including
total vocabulary and total conceptual vocabulary across word classes, and how
variables such as language environment and risk factors for language impairment
influenced the outcomes. Of particular interest are the longitudinal data in
this study which enabled us to assess the impact of the changing
language environment (measured by the Developmental
and Language Background Questionnaire created for the COST project) on the
acquisition of Irish and English vocabulary in individuals over time. The
results contributed to a larger crosslinguistic study on early vocabulary
acquisition in bilingual children within Working Group 3 of the COST Action
IS0804the COST Action.