This study analysed the gradual emergence of the teaching/learning process by examining theory of mind (ToM) acquisition and age effects in the preschool period. We observed five dyads performing a jigsaw task drawn from a previous study. Three stages were identified. In the first one, the teacher focuses on the execution of her/his own task without paying any attention to the learner, who simply observes the teacher's actions. In the second one, the teacher recognises the learner's status, thereby allowing the learner to begin using more ways of learning. This change reflects the establishment of the complementary relationship between the roles of teacher and learner that is crucial for the teaching/learning process prior to the teacher's acquisition of ToM. In the third stage, the teacher, who is now somewhat older and has fully mastered ToM, monitors the learner's behaviour from a distance, while the latter optimises her/his learning.