The educational system in Luxembourg is facing many challenges as the student population becomes increasingly heterogeneous, both socially and culturally. The inability of discourses on multilingualism to provide satisfactory solutions on how to best educate linguistic minorities in view of the social and demographic changes becomes evident. The new law in 2017 declared multilingual education mandatory with the focus on developing Luxembourgish, familiarizing children with French and valuing their home language. It is therefore necessary to help the teachers to constructively approach children’s daily multilingual practices particularly in their critical preschool years. Translanguaging pedagogy builds on the use of the full linguistic repertoire of linguistically diverse children in a number of ways. Translanguaging engages the children cognitively, linguistically, and socio-emotionally in order to reinforce their learning, achievement, and identity. This project advocates partnership-based research where the objectives are to: (1) provide professional development course on translanguaging to preschool teachers to help them design their multilingual classroom practices, (2) foster home-school collaboration by actively involving children’s families, and (3) reinforce children’s cognitive, linguistic and socio-emotional engagement in the classroom. The programme contains 8 sessions and it is divided into three parts: (1) the translanguaging classroom, (2) content and early literacy development, and (3) language development. To assess the effectiveness of the course, teachers (N=100) will be involved in focus groups and they will fill in a questionnaire before and after the course. To examine children’s cognitive, linguistics and socio-emotional involvement children will be tested by the PIPS test, a test of early literacy, numeracy and socio-emotional skills, before and after the course. This will be further explored through 8 video recordings of classroom sessions led by 18 selected teachers and their preschool group (N=15). Children’s families will be invited to share their home languages and cultures in sessions on multilingual ecology, translanguaging resources and language development. A wealth of research showed that children’s engagement, positive attitudes toward the school and close home-school collaboration increase their academic achievement. More specifically, research has shown that translanguaging develops deeper thinking, affirms multiple identities, and develops language and literacy.