The relation between teacher input and lexical growth of preschoolers

The present study examined the growth of receptive lexical skills in preschoolers over an academic year in relation to teacher speech. The participating students were English language learners and their monolingual English-speaking peers from the same classrooms. The measures of teacher input included indicators of the amount of speech (total number of words), lexical richness (number of different word types), and structural complexity (number of words per utterance). These measures were based on a speech sample collected during a classroom observation. For English language learners, vocabulary growth was positively related to the total number of words produced by the teacher, but negatively related to the number of words per utterance. For monolingual speakers, vocabulary growth was positively related to the number of word types produced by the teacher. The findings underscore the importance of considering different aspects of verbal input for understanding individual variability in language growth of preschool students.