In this study, classrooms were regarded as systems in which the teacher and students interact in context and behaviors of the teacher and students affect each other mutually in a cyclical or spiral manner. We attempted to capture nuances of interactional pattern that are not readily visible through the product-oriented approaches. To analyse classroom interaction dynamically and in real time, the State Space Grid technique was applied. Two pairs of teachers were especially focused on. One pair involved most versus least experienced teachers and the other was teachers whose students have highest versus lowest mean scores in motivation. The content and structure of teachers' interpersonal behaviours in the class were analysed in terms of Communion and Agency based on the Model on Interpersonal Teacher Behaviour. It was found that, for students' motivation, the effects of Communion were somewhat stronger, although Agency had its own role as the identified attractors imply. Additionally, classes of less and more experienced teachers differed primarily with respect to their structure and predictability (i.e. behaviours of the less experienced teacher had higher dispersion and entropy and behaviours of more experienced teacher were more predictable and consistent even to the extent that they sometimes seemed monotonous, especially when they were compared with the behaviours of the teacher of the most motivated class. This study has implications for enhancing the communicative ground of the class and teachers' and students' wellbeing and motivation.