A Longitudinal Study of Bilingual Development in Infants

The study focuses on longitudinal observations of bilingual development in two Russian infants, a brother and sister, until their vocabulary in the second language (English) numbered about 500 words. Though the children had a common background their exposure to English occurred at different ages and in different circumstances. Graphs of their vocabulary growth from 12 to 24 months of age and classification of their English vocabulary into semantic fields and parts of speech are given to illustrate the results of the observations. The research follows its subjects to their adult years and aims to contribute to understanding the effect of early bilingualism on further intellectual development.