Dual-Language Storybooks as a Word Learning Tool for Single-Language Learners

Bilingual storybooks, which are designed to be read in two languages, are considered a promising tool to support word learning. However, there is little empirical work examining how these books are structured and whether they can support children's vocabulary learning. The present study quantified the prevalence of different dual-language storybook formats and tested their impact on novel vocabulary learning in monolingual preschoolers. In Study 1, Spanish-English storybooks (
$N=129$
) were systematically sampled from local U.S public libraries and evaluated on their textual features. This content analysis revealed that most bilingual storybooks were structured to teach Spanish to English-speaking children and used full sentence translations. The content analysis was used to develop two experimental storybooks and to test their impact on novel vocabulary learning. In Study 2, English-speaking preschoolers (
$N=45,M_{age}=57.23$
months) were taught eight Spanish animal names (e.g., frog – rana) from two storybooks: a full translation book and a code-switched book. Although full translation books are more prevalent, children learned significantly more words from the code-switched book. A follow-up experiment with a new sample of preschoolers (
$N=45,M_{age}=56.45$
months) showed that code-switched books benefit learning when Spanish language input is reduced and the English and Spanish animal names are presented contiguously (“… a frog, una rana”). Taken together, this study tested the assumption that bilingual storybooks are an effective learning tool.