Synchronous online language lessons (SOLLs) are distinctly different from in-person lessons. Although digital tools, specifically, videoconferencing software, make doing SOLLs possible, these tools have specific affordances and constraints pertaining to how we engage, interact, and relatecreating new literacy practices. This study reports on a project which explored how five Hong Kong university English language teachers engaged in teaching SOLLs over a 13-week semester. The aim of the project was to understand and conceptualize the professional practices of synchronous online language teachers; specifically, our goal was to explore the relationship between identified practices and the competences needed to use digital tools during SOLLs to facilitate classroom interaction and therefore create appropriate conditions for language learning. The study expands our understanding of the professional practices teachers are engaged in when doing SOLLs. Furthermore, our data exemplify the context-specific teaching strategies and related competences needed to assist and mediate interaction in SOLLs. We propose that by improving synchronous online language teachers' interactional competence, they will be well-placed to help language learners achieve