The goal of the study is to examine how five preschool teachers were working with children's language development, both in their native language and in the Swedish language. The study will also examine how preschool teachers can perform their work in this area with the same quality no matter what level of knowledge they have of the different languages they encounter in their work. The study is a qualitative study and is based on the empirical of the interviews and observations of five preschool teachers in three preschools in Stockholm, Sweden. The analysis is divided into three themes; The significance of conversation, Communication with several ways of expressions and Individual way of working. In these themes we have described the different ways of work ing with language development that we encountered. The results of the study show that there are many ways, with similarities and differences, to work with children's language development. The results of the study also show that whatever knowledge the preschool teachers had in the different languages, they found ways to teach the children their language, both the Swedish language and their native language. The results also indicate that the size of the group of children could affect how the preschool teachers worked with language development.