Children's acquisition of nouns and verbs in Italian: contrasting the roles of frequency and positional salience in maternal language.

Because of its structural characteristics, specifically the prevalence of verb types in infant-directed speech and frequent pronoun-dropping, the Italian language offers an attractive opportunity to investigate the predictive effects of input frequency and positional salience on children's acquisition of nouns and verbs. We examined this issue in a sample of twenty-six mother-child dyads whose spontaneous conversations were recorded, transcribed, and coded at 1;4 and 1;8. The percentages of nouns occurring in the final position of maternal utterances at 1;4 predicted children's production of noun types at 1;8. For verbs, children's growth rates were positively predicted by the percentages of input verbs occurring in utterance-initial position, but negatively predicted by the percentages of verbs located in the final position of maternal utterances at 1;4. These findings clearly illustrate that the effects of positional salience vary across lexical categories.