Global response to the COVID-19 pandemic challenged and shifted social practices in many areas, but particularly in education with educational institutions forced to resort to computer-mediated communication to deliver teaching. This, in turn, heightened pedagogical and research interests in synchronous online teaching. The context of this presentation is language teachers’ socio-affective, pedagogical, semiotic, and technological competencies in synchronous online teaching, particularly their ability to provide “clear and concise instructions” (Guichon, 2009: 169). Our understanding of teachers' use of semiotic resources within the complex multimodal affordances of videoconferencing is limited. Indeed, from a multimodal perspective, earlier studies have analysed online teachers’ semio-pedagogical competence (Develotte, Vincent & Guichon, 2010), the way in which a single resource is employed (e.g. gaze, gestures, Wigham, 2017) or social or interactive aspects of language learning (Cappellini & Azaoui, 2017, Satar, 2016). Methodologically, they have largely provided descriptive analyses or conversation and discourse analysis of interaction. This paper implements multimodal (inter)action analysis (Norris, 2019) to analyse an experienced teacher’s instruction-giving (inter)actions in screen-recorded online language lessons conducted via Skype. We explore whether higher- and lower-level actions in task instructions-as-process differ when the same teacher repeats the same task with different learners. Our analyses demonstrate that task instructions appear more efficient during a second iteration: fewer higher-level actions are employed and, overall, instructions are shorter in length. In terms of lower-level actions, our results indicate that the teacher uses the same gestures or gesture types across iterations. Our findings also show (1) how semiotic misalignment may fragment or distort the shared interactional space and (2) how modal density misalignment can lead to different foregrounding of actions for the teacher and the learners. We will conclude with a discussion of the methodological opportunities multimodal (inter)action analysis offers to the investigation of online (language) teachers’ competencies and interactional practices.