The current study examined how mothers' production of four types of internal state words at multiple ages across the second year in a free play context was related to their infants' acquisition of those words. Twenty-nine mother-infant dyads were videotaped for 18 minutes during free play when infants were 13 and 17 months old. Mothers' total and…

The cross-categorical use of nouns and verbs poses a challenging problem to young language learners because they are known to be less willing to accept that a single form of a word be used for more than one linguistic purpose (e.g., one-form/one-function principle). The present study investigated whether children under 3 years of age are able to…