The research described in this paper investigates issues related to language socialization of four adolescent Polish immigrant children attending different post-primary schools in Ireland. The focus is on how heritage (Polish) language socialisation goals affect these children’s identity negation as they grow up in a multilingual environment, and as they try to find their place in a new country and society. In particular, this paper examines the ways in which the children construct themselves as authoritative or unauthoritative heritage language speakers The theoretical background, methodology, and final results are set from the longitudinal study (5 years) involving such students and their families, two of whom also attend weekend Polish schools in addition to mainstream secondary schools. The theoretical and analytical approach combines an Ethnography of Communication approach to data collection and field work, such as participant home and school observations, audio-recordings of children’s interactions with their peers, their teachers and parents, open-ended interviews, children’s samples of school work with Discourse Analysis approaches (Duff, 1995; Davis & Harre 1990, Harre & Langenhove, 1999, Ochs & Capps, 2001). A particular focus is placed on epistemic, moral and affective stances taken by the children in question. Certain aspects of agency, such as variable participation, allegiances with heritage language peer groups, affective and epistemic stances taken with respect to sociohistorical norms and values of the Polish language and culture are illustrated. The results of the analysis are interpreted in terms of heritage language socialisation (Ochs, Schieffelin, & Duranti, 2011), describing how different educational contexts may influence children’s identity negotiation. This micro-analysis of heritage children language socialisation is contextualized within a more holistic account of the Polish community in Ireland (Singleton, 2007) – a community culturally shaped by, and in turn shaping, wider societal and educational ideologies, values and power relations.