Cross-sectional associations between receptive and expressive lexical ability and specific grammatical structures at the age of 2;7–4;1

Expressive lexicon and grammar have a tight link in the initial stages of development (Bates & Goodman, 1999; Stolt et al., 2009). How this connection develops as children grow and progress to more advanced language use is not yet clear. Moreover, many studies concerning lexical ability are limited to expressive lexicon. The aim of this study is to provide novel information on the connections between lexicon (expressive and receptive) and specific domains of grammar (phonology, morphology) at the age of 2;7–4;1 (years; months).

Participants are typically developing Finnish speaking children (N=124). Data was collected at a single measurement point with children’s age varying between 2;7 and 4;1. Lexical skills were assessed using the Wechsler Preschool and Primary Scale of Intelligence-test (WPPSI-III; sub-tests: Receptive Vocabulary Task; Picture Naming Task) and the Finnish version of the MacArthur Communicative Development Inventories III (FinCDI III). Grammar was measured with the Finnish Phonology Test, the Finnish Morphology Test, and the FinCDI III (sub-sections: Phonology, Morphology, Language complexity, and Total score of language structures).

Expressive lexical ability had statistically significant associations to all grammatical structures with r-values varying between .24 and .73. The associations were stronger to morpho-syntax than phonology. The strongest associations were found between the FinCDI III Words and two subparts measuring morpho-syntax (r=.65; r=.66) and the Total language structures (r=.73) of the same test. Receptive lexicon’s connections to different aspects of grammar were more stable and varied between .31 and .41.

This study adds knowledge about the relationship between grammar and lexical ability in children aged 2;7–4;1. The results suggest that these domains continue to have a strong association beyond the first three years of age. However, the connections of expressive and receptive lexicon to phonology and morphology may differ.

References

Bates, E., & Goodman, J. (1999). On the emergence of grammar from the lexicon. In B. MacWhinney (Eds.), The emergence of language (pp. 29–80). Lawrence Erlbaum.

Stolt, S., Haataja, L., Lapinleimu, H., & Lehtonen, L. (2009). Associations between lexicon and grammar at the end of the second year in Finnish children. Journal of Child Language, 36(4), 779–806. https://doi.org/10.1017/S0305000908009161