Abstract: Light Warlpiri is a newly emerged Australian mixed language that systematically combines nominal structure from Warlpiri (Australian, Pama-Nyungan) with verbal structure from Kriol (an English-lexified Creole) and English, with additional innovations in the verbal auxiliary system. Lexical items are drawn from both Warlpiri and the two English-lexified sources, Kriol and English. The Light Warlpiri verb system is interesting because of questions raised about how it combines elements of its sources. Most verb stems are derived from Kriol or English, but Warlpiri stems also occur, with reanalysis, and stems of either source host Kriol-derived transitive marking (e.g., hit-im ‘hit-TR’). Transitive marking is productive but also variable. In this paper, we examine transitivity and its marking on Light Warlpiri verbs, drawing on narrative data from an extensive corpus of adult speech. The study finds that transitive marking on verbs in Light Warlpiri is conditioned by six of Hopper and Thompson’s semantic components of transitivity, as well as a morphosyntactic constraint.