What language do they speak?

Although Australia has no official language, English is so entrenched that it has become the de facto national language. Australian English is a major variety of the language with a distinctive accent and lexicon. General Australian serves as the standard dialect. Spelling is similar to that of British English with a number of exceptions. According to the 2006 census, English is the only language spoken in the home for close to 79 per cent of the population.

The next most common languages spoken at home are Italian (1.6 per cent), Greek (1.3 per cent) and Cantonese (1.2 per cent); a considerable proportion of first- and second-generation migrants are bilingual. A 2010–2011 study by the Australia Early Development Index found that the most common language spoken by children after English was Arabic, followed by Vietnamese, Greek, Chinese, and Hindi. Between 200 and 300 Indigenous Australian languages are thought to have existed at the time of first European contact, of which only about 70 have survived. Many of these are exclusively spoken by older people; only 18 Indigenous languages are still spoken by all age groups. At the time of the 2006 Census, 52,000 Indigenous Australians, representing 12 per cent of the Indigenous population, reported that they spoke an Indigenous language at home. Australia has a sign language known as Auslan, which is the main language of about 5,500 deaf people.