On the basis of a new view of the Swedish preschool’s commissions it has been argued that preschool children (1-6 years) shall develop knowledge of different content areas. For these reasons, there is a need of a discussion about what a changed commission can mean and what pedagogical consequences it may have for activities in preschools and teachers actions. Questions about what may constitute a relevant content and didactic are on the agenda.

One content area the commission highlighted is natural science and one important aspect of this is to make ecological phenomena visible in children’s everyday life. The aim of the present paper is to report on a study of verbal communication between teachers and children in preschool about ecological phenomena. Children are here seen as active in their own learning and that develops on the basis of their own experiences in communication with the surrounding world. A preschool unit was followed by video observation during two months when working on themes about life in a tree stump. 21 children (3-6 years) and three teachers participate in the study. The empirical data consists of video observations. Focusing the verbal communication the data observations have been transcribed. The transcriptions were analysed from the know-what and the know-how aspect of learning. The result is presented on the basis of the communication of the what-perspective and is discussed in terms of what is noticed and how the children’s understandings are communicated.  The connections between children’s ability to understand and communicate their observations, as well as the role of the preschool teacher dealing with a specific content are finally discussed.