The aim of this qualitative interview study is to investigate which methods some teachers in grades 4–6 say that they use to strengthen multilingual pupils’ development in language and knowledge. A central place in the study is devoted to these teachers’ choice of method and how they justify it. The study seeks answers to the following questions: How do teachers in grades 4–6 describe their work to strengthen multilingual pupils’ language and knowledge development? What obstacles and possibilities do the teachers think are afforded by the methods described?  The study proceeds from a sociocultural perspective, focusing on learning through interaction with others. The method on which the study is based is qualitative interviews with teachers in grades 4–6. The twelve participants in the study, who work as teachers at three different schools in Götaland, were interviewed in four focus groups where a semi-structured interview form was used.  The results of the study show that the teachers think that language- and knowledge-development teaching benefits all pupils and that the teachers want and need more training in how to work to develop language and knowledge, a finding that agrees well with research in the field. The teachers in the study cannot give an explicit and unambiguous explanation of language- and knowledge-development teaching, but they are in relatively good agreement in their description of factors that are fundamental for language- and knowledge-development, such as interaction and cooperation, support, pre-understanding, positive expectations and proceeding from the pupils’ knowledge and experience. The teachers see opportunities to develop the pupils’ language and subject knowledge through explicit teaching about the various concepts in school language, different forms of group work which give high pupil activity and interaction, and explicit teaching about reading and writing strategies, for example, work with model texts, the circle model and reciprocal teaching in reading comprehension. Other methods and aids used by the teachers are picture support, film, body language, concept boxes, small whiteboards, recorded teaching material in different languages, and cooperation with study advisers. Obstacles mentioned were limited availability of digital aids and shortage of time, which mean that the teachers were not able to give as much pre-understanding, adapted teaching, and support as they would have liked.