When linguists talk about grammar, they mean the system a language has for putting things together – the ways that speakers of a language combine words, and bits of words, to form sentences, and then put them together. The rules of a language are defined by the users – the people who speak, sign or write the language. Each language has its own distinct structures and patterns, though these can vary for different groups of speakers of a language. They can also change over time, which is why English today is so different from the English of a few hundred years ago, and even a little different from the English of a few decades ago. English varieties in Australia share many grammatical features with Englishes elsewhere in the world, but they also have their own flair.
Video: How to Speak Australian: Abbreviate Everything . This video shows a range of the well-known Australian shortnenings such as ‘brekky’ for ‘breakfast’ – these types of abbreviations are called ‘hypocoristics’. You can read a bit more about how these work in Australia in this interview with Evan Kidd, and this Fully (sic) post by Nenagh Kemp.
Reference: For a very detailed look at different parts of the system of English grammar, check out Grammarpedia, written by linguists at LaTrobe University. This will take you through the building blocks of the language, including the behaviour of different types of words, bits that can be added to words to change their meaning or behaviour, and the rules which determine how English words can be combined together into longer and more complex chunks of language.
Classroom info: Aboriginal English has a lot in common with other types of Australian English, but there are also distinctive features in the accent, vocabulary, grammar, and meaning used by speakers of this variety, and these can differ across the country.To learn all about Aboriginal English, including its history, use, and linguistic features, see this description of Aboriginal English written by Diana Eades.