One official language, several recognised regional languages
English overwhelmingly dominates public and private life without formal official status, a fairly common situation among English-speaking countries. The country nevertheless remains deeply multilingual because of immigration: nearly a quarter of the population speaks a language other than English at home, led by Mandarin, Arabic and Vietnamese. The Aboriginal linguistic heritage, rich in several hundred languages before 1788, was severely weakened by colonisation and survives today as living languages in only a limited number of communities, mainly in the Northern Territory.
English
The country's de facto language, but without official status in the Constitution or a federal law.
Mandarin
The most spoken language at home after English, reflecting the importance of Chinese immigration.
Arabic
Vietnamese
Aboriginal and Torres Strait Islander languages
Of the 250 to 300 or so languages spoken before colonisation, the vast majority are now extinct or severely endangered; Kriol and Yumplatok (Torres Strait Creole) are among the most widely spoken.