Prototype Effects On Semantic Change And Their Cognitive Motivations

More and more study has been made on semantic change. The purpose of this thesis is to analyze semantic change from a cognitive point of view based on the prototype theory. In history, semantic change has been explained based on traditional semantic theory, and has also been explained from both historical and pragmatic points of view, but there has been no satisfactory explanation.In this thesis, the first chapter deals with the definition of semantic change, main theoretical issues of semantic change, and some semantic theories on semantic change. In fact, semantic change is studied from three aspects: changes of a particular language in the course of time, the generalization or mechanisms of changes and the explanation or motivations of changes. The second and third aspects will be highlighted in the thesis.The second chapter is about mechanisms of semantic change. Based on review of literature on mechanisms of semantic change, two mechanisms at the simplest level will be discussed in detail, which are generalization and specialization. In fact, generalization is much more important and can be achieved by metaphor and metonymy. Therefore metaphor and metonymy as cognitive tools are considered as the most striking and important mechanisms of semantic change.The third chapter is about prototype effects on semantic change. First the prototype theory is explained fully in order to help understand those prototype effects much deeper. Then four prototypicality effects based on non-equality and non-discreteness of prototype structure are studied in detail, which are shown by polysemy.The fourth chapter is concerned with cognitive motivations of semantic change. In this part four cognitive motivations are analyzed, which are cue-validity, cognitive economy, perceived world structure and conjunctivity.In the last chapter, the summary of the above-mentioned is provided.