| The purpose of this longitudinal study was to mathematically model first and second language trajectories and interactions among developing sequential bilingual school-age children. Language data were collected in four waves, with a one-year interval between each wave. Participants (N = 34, mean age of 7.3 at Wave 1) lived in the US, spoke Vietnamese as a first and home language (L1) and began learning the majority community language, English (L2), in early childhood. Children completed measures in the L1 and L2 at lexical, grammatical, and discourse subsystems each year for four consecutive years. Multivariate hierarchical linear models were calculated to examine the shape and rates of change for the two languages nested within individual children. Associations within and between languages were examined across different language subsystems at each wave and over time in a series of correlational and longitudinal analyses. Results showed (a) positive growth across all language subsystems for the L1 and L2 with relatively more rapid gains in the L2, (b) moderate to strong positive associations between languages at each wave and over time, (c) bidirectional cross-linguistic transfer, and (d) changes in the nature of L1-L2 relationships with age. Findings are interpreted within a Dynamic Systems framework in which a child's language system emerges from multiple interactions across cognitive, social and language systems as well as interactions within and between languages (de Bot, Lowie, & Verspoor, 2007; Kohnert, 2007). |
