Research in educational linguistics is now challenging the efficacy of monolingual approaches that often dominate educational practices in multilingual settings. In most African nations where multilingualism is the norm, there remains a persistent reluctance by educational stakeholders (principals, teachers, parents, and students) to embrace multilingualism in education or to reposition local languages as resources in classrooms. This article draws on qualitative data from a multilingual, rural, fourth-grade classroom in Kenya to interrogate the articulated ideologies and their effects on communicative practices as voiced by the participants and by observing actual classroom practices. Bourdieu's notions of habitus, legitimate language, and symbolic power serve as analytic lenses for enhancing our understanding of the power of language ideologies. From the data, 'monoglossia' emerged as the key operating ideology, with time-on-task pedagogical practice helping to consolidate these monoglossic practices. The most visible effect of this ideology was silencing student engagement in the classroom. I argue that an awareness of these articulated ideologies and their observable effects on students' learning and language-use behaviors is important for challenging the subordination of home languages and the epistemic exclusion of the children who speak marginalized languages. Ideological awareness may open spaces for alternative and inclusive educational approaches.