This study of classroom discourse was prompted by a dilemma: the apparent contradiction between the language planning policy of an education department and the reality of language use in the classroom. Of the 83 schools in the Northern Territory that are located in predominantly Aboriginal communities, only 20 are identified as being 'bilingual' by the NT Education Department and even fewer have formal bilingual programmes that are operational. The rest are designated 'English-only'. This distinction between the 'bilingual' and 'English- only' programmes in Aboriginal schools is not, primarily, based on the language background of the students or their communities. The 'English- only' approach to Aboriginal education in the Northern Territory makes use of neither an English as a second language curriculum nor ESL qualified teachers. It does, however, provide for the appointment of a local Aboriginal ' teaching assistant' who is a fluent speaker of the vernacular and whose main job it is to make comprehensible to the students the non- Aboriginal teacher's discourse. In this provision there is some recognition that the 'English-only' classroom has more than one language of instruction. However, since many Aboriginal teacher assistants have limited English language skills and few are given any formal training, language learners in the 'English-only' classroom are often submerged in the target language well beyond the point at which input is comprehensible. This study seeks to look closely at the discourse patterns that are discernible in one ' English- only' Aboriginal classroom. In particular the focus will be on the way in which the whole-class setting of much classroom discourse, a setting which engenders particular behaviour patterns, precludes the successful participation of Aboriginal students and provides them with little opportunity to display their communicative ability. The study is centred on a small 'English-only' one-teacher school south-east of Tennant Creek and focuses on the discourse patterns that emerge from the whole- class interaction. These interactions, it will be shown, are determined and dominated by the non- Aboriginal teacher and do not encourage effective second language learning.