The aim of this thesis is to examine several aspects of situation semantics and to evaluate the contribution which the theory makes to our understanding of language, in particular whether it brings us nearer to a solution of some traditional puzzles with attitude reports. The presentation is in three parts. The first part, comprising chapters one and two, consists of a general introduction to the issues involved and tackles the question of where situation semantics places the boundary between semantics and pragmatics. The second and main part, chapters three to six, is devoted to demonstrating the language- dependent status of abstract situations. The interpretations of expressions and the role of the setting in composition are analysed in chapter three. In chapter four I consider Russell's views on propositions and the Russellian semantics Richards has given. Chapter five examines in detail the suggestion of chapter three that the level of abstract situations is not independent of language, recasts situation semantics accordingly as an interpreted language, and lastly considers an extension of situation semantics to include molecular facts. In chapter six situation semantics is related to direct reference semantics. Finally, chapters seven and eight treat attitude reports, analysing firstly the ingredients of Barwise and Perry's approach to the semantics of the attitudes, and secondly setting out some traditional puzzles and considering how situation semantics deals with them. The goal throughout is to clarify and understand what the ideas and insights behind situation semantics are and to determine their importance for semantic theory.