Young children's phonological awareness and nonword repetition as a function of vocabulary development.

The role of vocabulary growth in the development of two reading-related phonological processes was examined. In Experiments I and 2, 4- and 5-year-olds and a sample of first graders performed better on phonological awareness tasks for word versus pseudoword stimuli, and for highly familiar versus less familiar words. Three- and 4-year-olds in Experiment 3 performed better for words with many versus few similarly sounding items in a listener's lexicon. Vocabulary was strongly associated with nonword repetition scores for 3- to 5-year olds. The shared variance of this association was accounted for by phonological awareness measures and did not appear to be due to phonological short-term memory, as previously argued. The author proposes that vocabulary growth, defined in terms of absolute size, word familiarity, and phonological similarity relations between word items, helps to explain individual differences in emerging phonological awareness and nonword repetition.