ENThis research study examined the reflections of primary school pupils and teachers on the meaning and benefits of the cooperative learning method. The aim of the study was to explore the reflection of pupils and teachers on cooperative learning from a linguistic and cognitive point of view. The investigation was carried out in one of the major primary schools in Vilnius and involved 24 primary school children and 8 teachers. The responses to the questionnaire responses and interview questions in this mixed methods research study provided a first-hand look at why children find it important to communicate and cooperate on a variety of things. The conceptual theoretical framework of reflection and cooperative learning described in the study underpins practice by scientific evidence and is crucial for making decisions about the organization of the educational process. The empirical data were analyzed using explorative quantitative and a qualitative content analysis strategy. Primary school pupils identified the following aspects of language: asking for and giving help, asking questions to clarify content, and talking as a way of helping to learn. In terms of cognitive content, cooperative learning was perceived by pupils as helping them to find the information they need quickly and efficiently, to analyze it together. Cooperative learning was more challenging when there are many pupils with different needs in the classroom. Keywords: Reflection, cooperative learning, language abilities, cognitive abilities, primary school pupils, teachers. [From the publication]