This article seeks to engender scholarly and policy engagement with the neglected but important subject of subsidiary legislative power on different levels of English language capability for Australian visas. The question is, does the Migration Act 1958 (Commonwealth) permit regulations and legislative instruments on different levels of English language capability such as ‘competent English’? I argue that since section 5(2) of the Migration Act defines ‘functional English’ for purposes of the whole of the Act and Regulation 5.17 of the Migration Regulations 1994 (Commonwealth) has been made giving effect to it, the object of the Act on the level of English language proficiency a visa applicant must have is effectively and exhaustively addressed. Therefore, the Governor-General and Minister lack subsidiary legislative power to regulate different levels of English language proficiency. I also argue that the Governor-General cannot subdelegate regulation-making power under the Migration Act. I argue as well that the competent English regulations and instruments do not contain an exhaustive definition of what it takes to prove competent English and that by virtue of sections 54(1) and 55(1) of the Migration Act, the evidence to be used to prove a visa criterion is not limited to only the prescribed evidence.