Australian English (AusE, AusEng, AuE, AuEng, en-AU) is the set of varieties of the English language native to Australia. It is the country's common language and de facto national language; while Australia has no official language, English is the first language of the majority of the population, and has been entrenched as the de facto national language since British settlement, being the only language spoken in the home for 72% of Australians. It is also the main language used in compulsory education, as well as federal, state and territorial legislatures and courts.
Australian English began to diverge from British and Irish English after the First Fleet established the Colony of New South Wales in 1788. Australian English arose from a dialectal melting pot created by the intermingling of early settlers who were from a variety of dialectal regions of Great Britain and Ireland, though its most significant influences were the dialects of Southeast England. By the 1820s, the native-born colonists' speech was recognisably distinct from speakers in Britain and Ireland.
Australian English differs from other varieties in its phonology, pronunciation, lexicon, idiom, grammar and spelling. Australian English is relatively consistent across the continent, although it encompasses numerous regional and sociocultural varieties. "General Australian" describes the de facto standard dialect, which is perceived to be free of pronounced regional or sociocultural markers and is often used in the media.
The earliest Australian English was spoken by the first generation of native-born colonists in the Colony of New South Wales from the end of the 18th century. These native-born children were exposed to a wide range of dialects from across the British Isles. Similar to early American English, the process of dialect levelling and koineisation which ensued produced a relatively homogeneous new variety of English which was easily understood by all. Peter Miller Cunningham's 1827 book Two Years in New South Wales described the distinctive accent and vocabulary that had developed among the native-born colonists.