The role of explicit contrast in adjective acquisition: a cross-linguistic longitudinal study of adjective production in spontaneous child speech and parental input

Experimental studies demonstrate that contrast helps toddlers to extend the meanings of novel adjectives. This study explores whether antonym co-occurrence in spontaneous speech also has an effect on adjective use by the child. The authors studied adjective production in longitudinal speech samples from 16 children (16–36 months) acquiring eight different languages. Adjectives in child speech and child-directed speech were coded as either unrelated or related to a contrastive term in the preceding context. Results show large differences between children in the growth of adjective production. These differences are strongly related to contrast use. High contrast users not only increase adjective use earlier, but also reach a stable level of adjective production in the investigated period. Average or low contrast users increase their adjective production more slowly and do not reach a plateau in the period covered by this study. Initially there is a strong relation between contrast use in child speech and child-directed speech, but this relation diminishes with age. </jats:p

Ratings of age of acquisition of 299 words across 25 languages: Is there a cross-linguistic order of words?

We present a new set of subjective age-of-acquisition (AoA) ratings for 299 words (158 nouns, 141 verbs) in 25 languages from five language families (Afro-Asiatic: Semitic languages; Altaic: one Turkic language: Indo-European: Baltic, Celtic, Germanic, Hellenic, Slavic, and Romance languages; Niger-Congo: one Bantu language; Uralic: Finnic and Ugric languages). Adult native speakers reported the age at which they had learned each word. We present a comparison of the AoA ratings across all languages by contrasting them in pairs. This comparison shows a consistency in the orders of ratings across the 25 languages. The data were then analyzed (1) to ascertain how the demographic characteristics of the participants influenced AoA estimations and (2) to assess differences caused by the exact form of the target question (when did you learn vs. when do children learn this word); (3) to compare the ratings obtained in our study to those of previous studies; and (4) to assess the validity of our study by comparison with quasi-objective AoA norms derived from the MacArthur–Bates Communicative Development Inventories (MB-CDI). All 299 words were judged as being acquired early (mostly before the age of 6 years). AoA ratings were associated with the raters’ social or language status, but not with the raters’ age or education. Parents reported words as being learned earlier, and bilinguals reported learning them later. Estimations of the age at which children learn the words revealed significantly lower ratings of AoA. Finally, comparisons with previous AoA and MB-CDI norms support the validity of the present estimations. Our AoA ratings are available for research or other purposes