The place of language in Awyu-Ndumut speech communities of the Indonesian province of West Papua is investigated from the point of view of the parallel but interconnected worlds of clan lands and nation-state sponsored settlements, with institutions such as schools and churches. First, language and identity, language names, multilingualism, linguistic ideologies and special speech registers are discussed from the perspective of clan-based cultural and linguistic practices. Second, the relationship between Papuan languages and Indonesian is investigated from the perspective of the dynamics of the clan land/settlement opposition. Indonesian is talked about by Awyu-Ndumut speakers both positively and negatively. Positively, they speak of it as an interethnic lingua franca. Negatively, they speak of it as the language of “demons”, that is people outside the boundaries of Awyu-Ndumut social personhood.