title: The precocious two-year-old: status of the lexicon and links to the grammar.
abstract: This is a study of the lexical and grammatical abilities of 16 lexically precocious talkers. These children, aged 2;0 were compared to their age-matched peers, 22 typical talkers aged 2;0, and their expressive vocabulary-matched peers, 22 typical talkers aged 2;6. Individual differences in children's lexical knowledge at 2;0 were stable--evident in parent report, laboratory observation, and an experimental fast-mapping paradigm. In accordance with the continuity hypothesis, the lexically precocious children were also grammatically precocious, having a greater representation of grammatical types and tokens and more advanced combinatorial language than their typical age-matches. Their grammatical development was very similar to that of their older vocabulary-matched peers. Limits on continuity were highly constrained with no true dissociation between the lexicon and the grammar in 33 cases examined. We conclude that, among two-year-olds, grammatical development is more tightly associated with the size of the lexicon than with chronological age.
authors.affiliation: Northwestern University, USA. karla-mcgregor@uiowa.edu
authors.forename: Karla K
authors.initials: KK
authors.lastname: McGregor
authors.forename: Li
authors.initials: L
authors.lastname: Sheng
authors.forename: Bruce
authors.initials: B
authors.lastname: Smith
mesh_terms: D000367:Age Factors; D016022:Case-Control Studies; D002663:Child Language; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D014705:Verbal Behavior; D014825:Vocabulary