Aim: In this symposium, we will study the different statuses that can be attributed to the object of learning according to the context: is it a subsidiary element or the core of the LS? Methodology: Fist, Rosanna Margonis-Pasinetti will analyse a LS in which the object of learning is central: her group seeks to develop didactic sequences around plurilingual activities. Then, in the LS presented by Julien Buchard, the object of learning plays a diametrically opposed role: different groups explore the research theme by planning, observing and analysing lessons with different objects. Finally, Béatrice Rogéré Pignolet will present a 'hybrid' LS that illustrates a method of working with a specific object: her group tries to understand how to appropriate a new textbook by studying sequences. Findings: These three contributions will enrich the debate that will follow to discuss the place of the object of learning in Lesson Studies and its impact on the process and its outcomes. Significance and relevance for the 4th conference strand: Our symposium is part of a desire to promote the development of LS in the French-speaking world, in the service of the quality of education. To do so, we increase the understanding of LS by analysing the role of one of its main components: the object of learning, which can be different depending on the learning context.