This investigation explored the ways in which English language learners (ELLs) included in an English-dominant, mainstream second-grade classroom gained access to classroom activities and to the language that conveyed them, and the ways in which these students came to participate in the classroom context. These questions were investigated through the lens of the theoretical construct of community of practice, which emphasizes learning as participation in social practices. Qualitative methodologies such as observations, interviews with students and teachers, field notes, and videotaping and audiotaping of student-student and student-teacher interactions were employed. The findings of this study suggest that for ELLs in the English-dominant environment, their linguistic access to classroom activities and their progression toward meaningful participation were in many ways complicated by: (a) unequal participation in the classroom activities, (b) ambiguities in the purposes of instruction, and (c) vagueness in communication by teachers (i.e., lack of clarity when giving directions, poor word choices, and incomplete explanations). Consequentially, the general divide of shared knowledge among members of the class gave way to subcommunities that were parallel to one another, creating a disconnection between the participants of the classroom community.