Learning is a social and interactional endeavor, in which the learner generally receives support from his/her social environment . In this process, the learner's feedback is important as it provides information about the learner's current understanding which, in turn, enables the tutor to adjust his/her presentation accordingly , . Thus, through their feedback learners can actively shape the tutor's presentation - a resource which is highly valuable, if we aim at enabling robot systems to learn from a tutor in social interaction. But what kind of feedback should a robot produce and at which time? In this paper, we analyze the interaction between parents and their infants (8 to 30 months) in a tutoring scenario with regard to the feedback provided by the learner in three different age groups. Our combined qualitative and quantitative analysis reveals which features of the feedback change with the infant's progressing age and cognitive capabilities.