The Evaluative Functions Of Evidentiality

As a pervasive linguistic phenomenon in almost all languages, evidentiality has attracted great attention of linguists from all around the world, and has become a hottest topic in linguistic researches in recent years. The Appraisal Theory, which is established by the functional linguists of the Linguistic Department of Sydney University in Australia in the 1990s, has attracted many linguists'attention. This thesis aims to explore how evidentiality functions in the Appraisal Theory, including the Attitude, Engagement and Graduation system. We adopt qualitative method, and conduct the research on evidentitality in academic discourse. We select 20 thesis of the post-graduated students who major in English-linguistics from CNKI as our research data, which cover various field of linguistics.We find that various evidentials functions evaluatively in construing attitude engagement and graduation. Each in the categories of Appraisal system has something to do with certainty or degrees of certainty and in academic discourse the evidentitals may show particular views or attitudes to conduct evaluation.This thesis is divided into six chapters. In Chapter One, the research background and the research questions are introduced. And then, we provide research methods later and data collection. At the end of the first chapter, we outline detailed structure of the thesis. Chapter two reviews the literature on evidentiality, concerning its definition and classification. Also, a review of the evaluative research, especially on academic discourse, will appear in this section. In Chapter Three, we will have a detailed discussion of the theoretical framework of the thesis. We have an overview of further study.Martin's Appraisal Theory by introducing the three subsystems:Attitude, Engagement and Graduation. After that, we try to propose the framework of the thesis according to the three subsystems of the Appraisal Theory. The evaluative functions of evidentiality in construing Engagement will be separately discussed in Chapter Four, and Chapter Five is composed of two parts:the studies on evaluative functions of evidentiality in construing Attitude system and in construing Graduation system.In Chapter Six, we draw a conclusion by summarizing several tentative findings of the study and pointing out the limitations of the thesis and providing some suggestions for further study.