This paper focuses on subject extraction in Māori, the indigenous Polynesian language of New Zealand. Māori has a range of verbal and non-verbal predicate constructions. I argue that, whilst subject topicalisation is generally permitted in all constructions, subject questioning is restricted (see Bauer 1993, 1997). More specifically, I claim that subject questioning is permitted in verbal and prepositional predicate constructions, but prohibited in nominal predicate constructions, all else being equal (see also de Lacy 1999). I adopt and defend a cleft analysis of questions according to which the questioned constituent is the matrix predicate phrase and the matrix subject is a headless relative clause (Bauer 1991, 1993, 1997). I propose that the restriction on subject questioning results from intervention in this headless relative clause. I argue that the C head probes for a nominal feature rather than a traditional A'-feature. Consequently, nominal predicate phrases intervene with A'-movement of the subject, whilst verbal and prepositional predicate phrases do not. My analysis suggests that A'-movement is generally triggered using nominal features in Māori. I discuss this proposal from an emergentist perspective, i.e. one where formal features are not innately pre-specified but rather emerge during language acquisition guided by the Third Factor cognitive bias to ‘Maximise Minimal Means’ (Biberauer 2017; Biberauer & Roberts 2015, 2017).