The present study explores how minority schoolchildren in multilingual peer group interactions act upon dominant educational and linguistic ideologies as they organize their everyday emerging peer culture. The data draw from ethnographies combined with detailed analysis (CA) of video recordings in two primary monolingual school settings in Sweden. Bakhtin’s processual view of how linguistic norms are used for overcoming the heteroglossia of language is used as a framework for understanding how monolingualism is talked-into-being in multilingual peer groups. As will be demonstrated, the children recurrently participate in corrective practices in which they playfully exploit multiple linguistic resources (syntactic, lexical and phonetic features) and the turn structure of varied activities (conflicts, accusations, insults, classroom discourse) to play with and consolidate a collective critical view of not-knowing correct Swedish. Moreover, they transform faulty talk (repeating structural elements, recycling arguments, using parodic imitations, joint laughter, code-switching) to display their language competence, assert powerful positions and strengthen alliances in the peer group. It is argued that such forms of playful heteroglossic peer group practices are highly ambiguous and paradoxically tend to enforce power hierarchies and values associated with different social languages and codes, thus co-constructing the monolingual ideology.