This study of a Head Start preschool classroom describes how social relationships appear to be key in the development of Spanish-speaking children's oral English. The children's choices of Spanish-speaking playmates, who were playing with English speakers, initiated what have been described in the literature as optimal opportunities for English learning. The study examines how, on the occasions they attempted to play, the Spanish-speaking children spoke English and how their English developed over time. The results of this exploratory examination appear to corroborate Wong-Filmore's interactional model of second language development. They also support changes in the qualifications for and practices of Head Start teachers, as well as suggest further research. The purpose of this study is to understand how four Spanish-primary children's oral English production changed and how their social relationships with their peers and teachers may have influenced this change over a four-month period. The two girls and two boys were four years of age. For two of the children, this was their second year in the program, and the first year for the other two children. I used video-recordings and fieldnotes to document the children's interactions with their two teachers and 13 peers during a daily classroom event, and I created case study narratives to conduct a cross-case comparison. According to the phases of second language acquisition for preschool children, the oral English production of the two girls and one of the boys improved, whereas the English production of the second boy appeared to regress to an earlier phase of development. The evidence suggests that the children's oral English was influenced by their social relationships with their peers and teachers. In particular, four themes emerged: play, status, gender and teachers' language choice. When the four focal children played with certain peers, they created social relationships that appeared to affect the types of opportunities available for developing their English language. Additionally, the children with higher levels of English proficiency seemed to be granted higher status, and thus received more privileges than children positioned with lower-status. The two girls in this study appeared to have more optimal opportunities for developing their English language, whereas the two boys received fewer opportunities. Finally, the teachers' language choice---speaking Spanish or English---may have prompted the children's English language development. The implications of these findings offer practitioners working with second language learners ideas for how they can support the children's English language development.Ph.D.Bilingual educationEarly childhood educationEducationLanguage artsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/125475/2/3192754.pdf