In the last decades I have participated, as a linguist, in several activities related to indigenous teacher training and consultancy in indigenous education programs, in direct contact with their teachers. I have worked mainly in programs and schools of the Kaingang nation. I have experienced the practice of collaborative research with native speakers of the language in all these activities, and at the same time I have tried to promote the training of indigenous teachers as native researchers. Indeed, this training includes not only teachers, as in the workshops we do the presence of older native speakers is crucial, so that some of them, as genuine indigenous intellectuals, take full advantage of such moments of study. In this text, I have focused on ethical and scientific achievements obtained with this type of collaboration (which is exemplified by the "discovery" of a grammatical category of gender in the Kaingang language), with easily deducible consequences regarding the quality of school education in indigenous communities, especially as a contribution to strengthening and revitalizing their languages.