Complex morphology, complex processing: Phonological hardening and ŋu‑insertion in Wubuy

This paper investigates how speakers of Wubuy (Nunggubuyu) process two linked morphophonological alternations—phonological hardening and ŋu-insertion—using two Two-Alternative Forced Choice experiments. Wubuy is highly polysynthetic; many stems alternate between root-initial continuants and place-matched stops (e.g., -waɭaŋi versus -paɭaŋi ‘to paint’) or require the meaningless syllable /ŋu/ before underlying stop-initial morphemes. Experiment 1 tested over‑ and under‑application of continuant-stop alternations with and without a 500 ms pause, which is introduced to increase processing time; Experiment 2 probed preferences for ŋu-insertion across faithful stops, hardened forms, continuants and single‑feature mispronunciations. Results show listeners prefer grammatical outputs but display asymmetric acceptance: processing of hardened verbs incurs processing cost and benefits from extra pause, while vowel‑initial verbs behave as if dual‑listed and are unaffected by pause. For ŋu-insertion, speakers strongly prefer grammatically required /ŋu/, tolerate single‑feature mispronunciations to varying degrees, and show gradient rather than categorical judgements. Overall findings favor a model in which canonical forms are stored and context‑sensitive phonological rules are applied during processing, with selective contributions from listing for some alternations. The experiments provide typologically rare results from an Australian language and argue for integrated dual‑route accounts. The research limitations include small participant numbers and culturally constrained data collection.