He is a linguist specializing in the indigenous languages of North America, many of which are no longer being spoken today due to various forms of economic and political coercion. He is committed to the idea that language reclamation and revitalization efforts in the United States and worldwide are an assertion of people’s fundamental right to communicate with each other using whatever language suits them. His research and teaching in support of these efforts are thus a means of assisting indigenous communities’ broader goals of preserving their cultural heritage and achieving self-determination.