Most Indigenous Australian languages are really different in their spelling from English. They have different sounds and so they need different letters in their alphabets. When British people came to Australia and started to write the indigenous languages down, they encountered many problems and couldn’t find a good way of doing this.
The spelling Jangga with a J comes from Norman Tindale, an anthropologist who surveyed languages and people across the whole of Australia. He made a spelling system to cover the whole of all the languages in Australia – it works better for some languages than others. Tindale used the J to refer to a soft sound like Y.
Other people spelled the language Yangga with a Y, as they heard it. This doesn’t mean there are two separate languages, or two separate words, it just means that there are two different ways of spelling the same name.
The main aim of writing a word is so that it can be read and pronounced and understood easily. Now people sometimes spell the language name with a Y: Yangga, and the name of the community of people is spelt with a J: Jangga.
Either way, the name can still be read and understood.
Dr. Angela Terrill, Linguist