Language endangerment has been a concern for many small-scale communities. But only little attention has been paid to new ways of speaking that different communities invent as their own creative responses to endangerment. In my research among the indigenous Aché communities in Paraguay, I have not only worked to document their heritage language, Aché, but also a newly emerging mixed language, Guaraché, that children learn as their first language. I am particularly interested in how children experiment and play with linguistic resources from different origins that they encounter in their environment and what that tells us about language emergence, linguistic differentiation, and metalinguistic awareness.