This case study explores the construction of intersubjectivity, defined as the creation of shared mental spaces, inside an undergraduate EFL writing class. To this end, four activities within the writing unit of a skills-based undergraduate EFL course were observed and subsequently transcribed. Preliminary findings were triangulated with the teacher and the group of participants, whose interaction was observed, using interviews, focal group discussions and stimulated recall techniques. Regarding the achievement of shared understanding, learners were found to focus especially on the joint comprehension of task procedures and target concepts, whereas the teacher emphasized procedures in her instruction, giving little emphasis to conceptualization. In regard to the engagement of teacher and learner perspectives throughout the unit, mismatches were observed between each other’s conceptions of the task goal, the problems encountered and the satisfactors sought the ongoing rules of the task and roles in interaction; all of which were hypothesized to constrain the achievement of intersubjectivity. Finally, concerning supportive intersubjectivity, differences in the provision of cognitive, strategic and evaluative support were found between learners and the teacher, with learners being more aware of their peers’ mental states at the moment of supporting each other. The findings in this study support the claims that, on the whole, teachers and learners construct intersubjectivity in different ways, and that it is important for teachers to position themselves in such a way that their culturally assigned higher status in interaction with learners does not thwart the construction of intersubjectivity.MaestríaMagister en la Enseñanza del Ingle