Previous studies have found that students whose home language differs from the language of instruction are prone to school inadequacy and to dropping out early (Cummins, 2015; EC, 2013) This is especially true for the lusophone population in Luxembourg. This thesis aims to capture the experiences of these migrant children in the Luxembourgish educational system to identify possible matches as well as mismatches between children’s support structures at home, school and daycare centre. Drawing on a sociocultural framework that understands that children learn languages when engaging in social practices with members of their communities (Rogoff, 1990) and that gives a prominent role to children’s active role when interacting with their environments (Van Lier, 2004), this thesis investigates the role of the adults in shaping the immediate environments of three newly arrived five-year-old Brazilian children in Luxembourg. It presents two cases studies that examine the supporting structures that parents at home, teachers at school and educators in Maison Relais pour Enfants (a non-formal education institution) provide to support language development of these children. The data from this qualitative study was collected from October 2017 to July 2018, combining participant-observation, fieldnotes, video recordings, photographs, questionnaires and interviews. The data analysis drew on approximately 170 hours of field observation, 25 hours of video material, photographs, interviews, and questionnaires. It was then analysed by employing different qualitative methods, i.e. Qualitative Content Analysis (QCA) (Vaismoradi & Snelgrove, 2019), Sociocultural Discourse Analysis (SDA) (Mercer, 2004), and Thematic Content Analysis (TCA) (Anderson, 2007; Vaisomoradi & Snelgrove, 2019). The findings show that the adults designed physical learning spaces and selected material that afforded language and literacy development. They also offered language-related activities such as phonemic awareness exercises, tracing letters, ...