Examining the productive speech of bilingual mother-child dyads and the factors influencing child lexical diversity

• Main Author: Sim, Xin Yi
• Other Authors: Setoh Pei Pei
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Social sciences
• Online Access: http://hdl.handle.net/10356/74097
• Institution: Nanyang Technological University

While the influence of biological and cognitive predispositions on language acquisition is irrefutable, literature has consistently demonstrated individual and crosscultural variations in the lexical characteristics of early productive vocabulary and the timing in which expressive language milestones are achieved. The present study aims to investigate the productive vocabulary of 30 Singaporean English-Mandarin bilingual children aged 15 to 24 months. Additionally, the study explores the influence of maternal linguistic input, emotional availability (EA), and socioeconomic status (SES) on bilingual children’s lexical diversity. Naturalistic observations of free-play sessions were used in conjunction with MacArthur-Bates Communicative Development Inventory (CDI) to assess the types and tokens produced by mothers and toddlers in English- and Mandarin- speaking conditions. Types and tokens in each word class were then tabulated to evaluate if the mothers and toddlers present a noun or verb bias when conversing in each language. A demographic questionnaire was administered to measure the SES of the mother-child dyads. The results showed that Singaporean mothers and toddlers exhibited greater diversity in their English productive vocabulary compared to their Mandarin productive vocabulary. Additionally, the mothers presented noun-verb symmetry when conversing in English and produced a pronounced verb bias when speaking in Mandarin, while the toddlers exhibited a noun bias in both language conditions. Furthermore, the present study showed that maternal linguistic input, EA, and monthly household income predicted the size of the toddlers’ English productive vocabulary, while their Mandarin productive vocabulary was predicted only by monthly household income.