Light Warlpiri, a new Australian mixed language combining Warlpiri (Pama-Nyungan) with varieties of English and/or Kriol that has emerged within approximately the last thirty-five years, shows radical restructuring of the verbal auxiliary system, including modal categories that differ from those in the source languages. The structure of Light Warlpiri overall is that of a mixed language, in that most verbs and some verbal morphology are drawn from English and/or Kriol, and most nominal morphology is from Warlpiri. Nouns are drawn from both Warlpiri-lexicon and English-lexicon sources. The restructuring of the auxiliary system draws selectively on elements from Warlpiri and several varieties and styles of English and/or Kriol, combined in such a way as to produce novel constructions. It may be that when multiple sources provide input to a rapidly emerging new system, innovative categories are likely to appear.