The Interrelation Between Lexical and Grammatical Abilities in Early Language Acquisition
According to the "specificity hypothesis" (Gopnik & Meltzoff 1986), there are highly specific links between early language and cognitive development as well as be-tween developmental milestones in different linguistic areas. Since the acquisition of grammar depends on a critical mass of stored lexical entries, children with lexical delay are at risk for persisting language impairment. However, it is still difficult to distinguish those children who overcome their initial delay from those who will show signs of con-tinuing language problems.
The longitudinal study presented in this paper aims to investigate specific inter-actions between early lexical and grammatical development in German and to identify critical areas of language development, in which the difficulties of language impaired children become evident. 15 children with normal development participated in the study. The children were recruited at 2;0; they were observed at age 2;2, 2;4, 2;6, and at 3;0 for follow-up. Methods comprised observational, elicitation, and spontaneous speech data. Lexical, semantic, and syntactic abilities were tested with various tasks. 3 Children with lexical delay (Late Talkers) were also identified at 2;0, when they met the criterion of less than 50 words and/or no word combinations. The LT passed the same procedure as the normally developing children.
The results show significant improvements of language abilities in the third year of life. At the same time, the LT lag behind their normally developing peers in all lan-guage domains without clear signs of recovery until age 3. Significant correlations were found within and between language domains. The results indicate that there is evidence for homotypic as well as for heterotypic continuity (see Bates al. 1988). The present study’s data point to developmental associations between lexical and grammatical achievements in normal and impaired language acquisition. In addition, clinical impli-cations for diagnosis and prognosis of Late Talkers are mentioned.
Bates, E., Bretherton, I., & Snyder, L. (1988). From first words to grammar: Individual differences and dissociable mechanisms. Cambridge: Cambridge University Press.
Gopnik, A., & Meltzoff, A.N. (1986). Relations between semantic and cognitive devel-opment in the one-word stage: The Specificity Hypothesis. Child Development, 57, 1040-1053.