Language endangerment is a concern for many minority communities around the world. But only little attention has been paid to new ways of speaking that many of these communities invent as their own creative responses to ongoing transformations of modes of subsistence, social organization, and cultural understandings. In my research with the Indigenous Aché in Paraguay, I have not only helped to document their heritage language, Aché, but also worked with children and their caregivers to understand the socialization patterns contributing to language shift towards the national language, Guaraní, as well as the emergence of a new mixed language that incorporates elements from both, called Guaraché. This new language is now learned by children as their first language and they have begun to create new patterns that are distinct from the input received from adults. In this context have also analyzed children’s language play and experimentation with linguistic resources from different origins, with a focus on the development of metalinguistic awareness, linguistic differentiation, and language emergence.