The aim of this chapter is to study language interactions in preschool as arenas for language learning and early literacy. We present theories about how children learn language and early literacy in preschool based on research by Vygotsky and his successors. Theoretical perspectives are discussed based on studies in Norwegian and Russian preschools. This chapter focuses on children’s learning about the native laws of language. We found that the teachers’ support to children’s language learning and language mastery is a complex and multifaceted process. Certain principles for mastery and methodical recommendations may help teachers develop children’s language and communication skills.