The process of adaptation to the partner in the course of an interaction is still not well understood. In the case of explanatory dialogues, to provide satisfying explanations, explainers have to consider the needs of the explainees. This requires mental representations of the explainees, i.e., “partner models”. Little is known about whether and how modifications of partner models during an explanation take place. We assumed that they get informed by the interactive behaviour of the explainee and investigated partner models in relation to explainees' verbal moves. A total of 59 dyadic explanations were investigated in an observation study. The comparison of the partner models before and after the explanation showed changes regarding, e.g., knowledge, interest in the explanation, cooperation, and mood. Moves such as questions as well as summarising and paraphrasing information given by the explainees were associated with the partner model dimensions interest in the explanation and co-construction.