This paper describes an analysis of teaching instances that were part of an in-service preschool teachers programme. The overall aim of the project was – together with teachers – to study model-based teaching and collaborative inquiry learning of chemical processes and physical phenomena in preschool, in relation to an object of learning. Central was the teaching of science in preschool, with particular focus on use of digital tools and the verbal communication as well as obstacles ‘threatening’ the intersubjectivity between teachers and children during learning situations in preschool. Our results show the need for the teacher to address what we call ‘intermediary objects of learning’ and the role of chosen wording andabstract models are emphasised. In addition, the paper highlights different communication categories used by teachers and children during science activities. How the communication varies with e.g. children’s age during teaching will be discussed at the conference.