title: A crosslinguistic study of the relationship between grammar and lexical development.
abstract: The relationship between grammatical and lexical development was compared in 233 English and 233 Italian children aged between 1;6 and 2;6, matched for age, gender, and vocabulary size on the MacArthur Communicative Development Inventories (CDI). Four different measures of Mean Length of Utterance were applied to the three longest utterances reported by parents, and to corrected/expanded versions representing the 'target' for each utterance. Italians had longer MLUs on most measures, but the ratio of actual to target MLUs did not differ between languages. Age and vocabulary both contributed significant variance to MLU, but the contribution of vocabulary was much larger, suggesting that vocabulary size may provide a better basis for crosslinguistic comparisons of grammatical development. The relationship between MLU and vocabulary size was non-linear in English but linear in Italian, suggesting that grammar 'gets off the ground' earlier in a richly inflected language. A possible mechanism to account for this difference is discussed.
authors.affiliation: Department of Development and Socialization Processes, University of Rome La Sapienza, Via dei Marsi 78, Rome, Italy. antonella.devescovi@uniroma1.it
authors.forename: Antonella
authors.initials: A
authors.lastname: Devescovi
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Caselli
authors.forename: Daniela
authors.initials: D
authors.lastname: Marchione
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pasqualetti
authors.forename: Judy
authors.initials: J
authors.lastname: Reilly
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bates
mesh_terms: D002663:Child Language; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007802:Language; D007807:Language Tests; D008037:Linguistics; D008297:Male; D012044:Regression Analysis; D014825:Vocabulary