This study investigated the developmental pattern of early lexical production and composition in Mandarin-speaking children. Forty Mandarin-speaking children and their parents participated in this one-and-a-half-year longitudinal study, and naturalistic samples of parent-to-child speech in toy play were collected when the children were 1;8, 2;2, and 3;0. The results showed that children’s lexical production increased significantly between ages 1;8 and 3;0. The proportion of closed-class words increased significantly with age, whereas the proportion of common nouns showed the inverse pattern, indicating the role of grammatical words increased as the children grew. Furthermore, nouns and verbs were predominant in Mandarin-speaking children between ages 1;8 and 3;0, and Mandarin-speaking children used more verbs than nouns at 2;2 and 3;0 in the toy play context. The longitudinal study clarifies early lexical development in Mandarin-speaking children, which provides a valuable contrast for different language systems.
