The introductory chapter of this thesis presents the central premise of the study - that classroom learning is constructed through talk - and states the primary aims. These are to provide an ethnographic account of the process of learning in a mainstream classroom, and to apply to this account a specific theoretical framework with a view to refining its central constructs. The thesis proceeds with a discussion of the methodological basis of the investigation - ethnographic case study - and the procedures used for data collection and analysis. This is followed by a discussion of the theoretical orientation of the study, which explains the complexity of the learning context of isolated bilingual schoolchildren and the rationale for a sociocultural approach to explore it. The neo-Vygotskian constructs central to this study - the zone of proximal development, scaffolding and appropriation - are introduced and explained, as are supporting concepts. Each of the three following chapters of the thesis is divided into three parts. The first examines in detail one of these constructs, and also related concepts, with a view to their potential relevance to the specific context of learning. The second part in each chapter comprises a detailed ethnographic description, micro genetic analysis and interpretation of the context and continuity of the learning discourse. The third part in each chapter comments on the implications for the constructs at issue. These three chapters constitute a narrative of the way that classroom learning is constructed through talk over a school year. The thesis concludes with a review of the pedagogical and theoretical implications arising from the investigation, and considers the utility of a neo-Vygotskian framework for further research into classroom learning.