This book deals with the language of the Gandanguurra people who pre-1788 occupied the Blue Mountains area between Bell's Line of Road in the north and Goulburn in the south, and from the Nepean River in the east to the catchment of the Abercrombie River in the west. Only about 1000 to 1200 Gandanguurra words have survived and most of these are listed in an appendix. Only a modest remnant of the grammar was recorded, mainly by R.H. Mathews and Mary Everitt c. 1900 from informants in the Burragorang Valley (south-east of Katoomba). Additional grammar was gleaned by the author over a period of some years via a study of Gandanguurra words, phrases and sentences recorded especially by Mathews and Everitt, and A.L. (Len Bennett), who had property in the Kedumba Valley, and who for many years in the early 1900s was friend and mentor of Billy Russell who was then chief of the Burragorang Valley local group. These circumstances led to the great majority of the surviving Gandanguurra grammar and vocabulary being based on the Burragorang Valley language. Gandanguurra grammar differed in several areas but particularly in respect of retroflex consonants & stop consonants. Its verbs included 'have' (a rarity). It's case marking included (a) a genitive suffix on a direct object / (b) a vocative case / (c) an instrumental case on a direct object.'