This thesis is an exploration of the use of figures of speech, idioms, commonly used metaphors, and various types of cliched, formulaic, and largely figurative language, in naturally occurring conversation. It investigates both the interactional environment and the position in which these expressions are employed. Chapter one explores some of the existing literature on idioms from a variety of disciplines including linguistics, sociology, psychology, and philosophy. It reveals that, despite these analyses, authors have failed to consider figures of speech on the occasions of their actual use. Thus I select a methodology which will allow me to fulfill this research aim. Chapter two begins the analysis of the interactional environment of idioms etc in conversation, revealing that these expressions recur in particular conversational topics: complaints, troubles-tellings, disagreements, and so on. The "fit" between idioms and this sequential environment is then explored, and it is discovered that idioms are well suited for use in rather "delicate" situations. In chapter three I demonstrate that idioms also recur in a particular sequential position: at the completion of topics. Topic changes involving idioms are then explored, and it is found that they are, in many ways, distinct from more common (stepwise) transitions: they are brief (occurring within three or four turns) and they involve disjuncts prior to the introduction of the new topic. It is then suggested that one reason for the association between idioms and topic changes is that they summarise the previous topic. Chapter four notes that idioms sometimes contain puns, and this conclusion is used to further investigate the relationship between idioms and the talk in which they occur. Having concentrated on idioms in informal conversation, chapter five seeks to establish whether the findings of the previous chapters can be applied to idioms in a more formal setting. Thus idioms in radio news interviews are examined, and some general statements, relating to idiomatic language and the nature of formal talk, are made. (Elizabeth Holt)