Dyirbal actually has only four places of articulation for the stop consonants and nasal consonants - this is fewer than many other Australian Aborigine languages, which have six. The difference is because Dyirbal lacks the apical and laminal split found in many other Australian languages.
The language is best known for its system of classification, similar to grammatical gender. The noun class usually labeled "feminine", for instance, includes the word for fire and nouns relating to fire, as well as all dangerous creatures and phenomena. This inspired the title of the George Lakoff book "Women, Fire and Dangerous Things". Some linguists distinguish between such systems of classification and the gendered division of items into feminine, masculine, and sometimes neuter found in, for example, many Indo-European languages.
Dyirbal is remarkable because it shows a split-ergative system. Sentences with a first or second person pronoun have their verb arguments marked for case in a pattern that mimics nominative-accusative languages. That is, the first or second person pronoun appears in the least marked case when it is the subject (regardless of the transitivity of the verb), and in the most marked case when it is the direct object. Thus Dyirbal is morphologically accusative in the first and second persons, but morphologically ergative elsewhere; and it is still always syntactically ergative.