This qualitative case study investigates the functions of language use and underlying raciolinguistic ideologies in interactions between Latinx emergent bilinguals who are Spanish native speakers and mainstream students in the fifth-grade English classroom in a public elementary school in the U.S. Midwest. Data included audio and video recorded observations and field notes from students' interactions in different contexts of the school, as well as students' work samples and test scores, English curricula, and interviews with the students and their English teacher. Data analysis encompassed open coding followed by focused coding, and this work was informed by critical discourse analysis, resulting in the emergence of themes of two major language functions. These functions were to establish the legitimacy of knowledge source and disqualify a minoritized group. Unbeknownst to their well-meaning English teacher, the students displayed curious forms of social agency. Pervasive and important ideologies underlie language functions and language became the site of symbolic power struggles through students' hegemonic and counter-hegemonic discourses. This study is significant in the country's present social and political climate of racial tensions and prejudice against minoritized groups. The study ends with practical and research implications.