Professor Dixon’s book The Dyirbal Language of North Queensland (CUP 1972) is acknowledge to be a classic study. His study of Yidin is directly comparable in importance. Yidin, which is also a dying language, is Dyirbal’s northerly neighbour. Yet the two languages have striking and fundamental differences in each area of grammar (while still both belonging to the Australian language family). In the phonology, there is a preference for each word to consist of an even number of syllables, in order to satisfy the stress targets of Yidin. Syntactically, the language is of a ‘mixed ergative’ type that cannot easily be accommodated in terms of standard syntactic theory. These and a number of other special features of Yidin have a crucial bearing on several theoretical enquiries into linguistic universals.