What is the role of the linguistic environment in children’s
early word learning? Here we provide a preliminary analysis
of one child’s linguistic development, using a portion of
the high-density longitudinal data collected for the Human
Speechome Project. We focus particularly on the development
of the child’s productive vocabulary from the age of 9 to
24 months and the relationship between the child’s language
development and the caregivers’ speech. We find significant
correlations between input frequencies and age of acquisition
for individual words. In addition, caregivers’ utterance length,
type-token ratio, and proportion of single-word utterances all
show significant temporal relationships with the child’s development,
suggesting that caregivers “tune” their utterances to
the linguistic ability of the child