While scholars have highlighted the importance of the language environment in the preschool classroom, there remains a dearth of research on the precise nature of the language children encounter in these early academic settings, especially during transitions (i.e., periods when children are involved in personal or classroom activities as they move from one setting to another across the preschool day). This study examined a teacher’s linguistic practices during transitions in a preschool classroom located in a public school, based on video observations and transcripts of teacher talk. Overall, the study found that teacher talk during transition periods is significantly less rich than during other activity settings combined. However, results also suggest that teacher talk varies within transition type. Interestingly, the teacher still managed to a limited extent to seize opportunities to engage in rich extended conversations with students during transitions. These findings point to the need to include transitions in studies of teacher language in preschool, especially given the considerable amount of time spent in such instances throughout the day.

The United States has witnessed a rise in dual language immersion (DLI) programs in recent years, with instruction delivered both in English, the majority language spoken in the wider society, and in another language, often referred to as the partner or minority language. But while accountability mandates have focused on students’ performance in core subjects (language arts, math and science), scant attention has been paid to the development of both languages of instruction. The present dissertation seeks to fill this gap by focusing on the French and English lexical trajectories of early elementary school children attending a DLI program (N = 39), with special attention paid to the impact of linguistic support in French, or lack thereof, outside of school itself. Based on parental responses on surveys, information was gathered on the amount and nature of the French language experience received outside of school. Next, using a multilevel model for change, the lexical trajectories of K-1 students in the DLI program is analyzed over one calendar year. Finally, relationships between French and English lexical outcomes are examined. Results suggest that participants’ experiences with the French language remain limited outside of school, even for students coming from French-speaking households. In terms of French lexical trajectories, students from French-speaking households (N = 15) score higher at baseline compared to their peers from non-French-speaking households (N = 24), but they do not display growth over the calendar year; whereas students from non-French-speaking households display progress in their expressive French vocabulary (but not in their receptive vocabulary). In terms of English lexical trajectories, no differences emerged based on students’ home language backgrounds. Participants displayed growth in their receptive English vocabulary, but not their expressive English vocabulary. Finally, results from correlations suggest that the relationship between French and English outcomes is stronger for students from French-speaking households than their peers from non-French-speaking households. This dissertation more fully elucidates the heretofore understudied relationship between out-of-school language experience and vocabulary development for students enrolled in a dual language program. Implications for research and practice with bilingual education are discussed, including the need to examine students’ language development in other domains and to focus on vocabulary instruction.