This chapter looks at what is thought about why it is important for children to retain their first language and have access to it for learning. It provides some examples of ways of doing this, examines immersion programmes, heritage language programmes, and the role of bilingual adults in learning. The chapter explores ways of promoting the use of mother tongue by children in schools and settings in order to benefit socially and cognitively. Mother-tongue support in schools and settings is limited, sometimes dependent on where the school is situated and what its approach to languages is. The mother tongue is supported mainly through encouraging children to speak and use their first languages in and out of class and through employing speakers of these languages as teachers or nursery nurses or teaching/support assistants. The mother-tongue teacher displayed a lot of code-switching and there was a good deal of team teaching.