Positioning is a dynamic socio-interactional phenomenon that can be assumed, challenged and transformed by participants during a social encounter. Even in very typical hierarchical situations, such as those in institutions, there is always room for improvisation and changes that break the ritual, altering the expected manner by which participants are supposed to interact. These changes cause (re)negotiation of the institutionally imposed positionings. In this article, we discuss data collected from a Portuguese as a Foreign Language (PFL) class in a Luso-Chinese primary school in Macau. Using an ethnographic microanalysis, moment-by-moment data is interpreted, identifying aspects that redefine the statuses of participants during classroom encounters. The results indicate that even being the central figure of the interaction, the teacher cannot maintain her gatekeeper positioning throughout the lesson. Many verbal and non-verbal elements present during the interaction exercise influence over the (re)organisation of the participants' positionings, enabling the students to negotiate the power usually delegated only to the teacher. This kind of behaviour can be considered ‘exuberant’ once it is not limited to the rules imposed by a traditional teaching system. It also casts doubt on the social and psychological determinism that is present in studies carried out in Chinese teaching/learning settings.