A Systemic-functional Approach To The Roles Of Context In Achieving Text Coherence

This thesis, based on the Systemic Functional grammar, aims to explore the roles of context in achieving text coherence with reference to Halliday's context theory. It conducts an analysis of RP abstracts.Halliday defined text as language that functions in some context (1985). That's to say text expresses language meaning under some special context. And a certain text needs to be correspondent with a certain context, which is called situation of context or register. It includes three variables: field, tenor and mode which are associated systemically with the functional components (ideational, interpersonal and textual). These three variables through the interface of the functional components influence the language system. To some extent the coherence of text is just the result of the context's functions.On the textual level the functional components relate to the context in this way: field is represented by ideational function, tenor by interpersonal, mode by textual; while on the lexico-grammatical level, the ideational function is realized by transitivity system, interpersonal by mood and modality system, and textual structurally by thematic structure and non-structurally by cohesive ties, etc. Hence, through the way of analyzing the transitivity system, mood and modality and thematic structure, etc. we can illuminate the context's roles in achieving the coherence of text.The result of the transitivity analysis indicates that the transitivity process choices should be correspondent with the need of the field of text. In the RP abstract the writers use a large amount of material and relational processes which account for about 80% in total to show what their researches are and relations among the research variables.The result of the mood and modality analysis indicates that the choices of mood and modality depend on the tenor of text. Distinct mood and modality convey different interpersonal meanings. The aims of academic writing is to supply the readers with the research phenomena and the natural results, namely with information, so the texts are usually written in declarative mood; also owing to the objective and open features of academic research, the writers avoid using subjective words with intensity.The result of the thematic structure analysis indicates that the theme choices of text have a great impact on the textual structure. They can influence the coherence of text, and understanding and acceptableness of readers. Hence, the textual organization should be fit into the mode of text. The writers of RP abstracts, most of them adopt the topic theme which is a replacement of the title with different wordings. In this way, not only texts are concise and clear, but also it is more convenient and effective for readers to get information.In this thesis, we have collected data from RP abstracts which have not been fully explored by Systemic Functional researchers. Through the analysis of this kind of data, we can not only increase the knowledge of academic abstract writing, expand the relevant research, but also enhance the understanding of this study.In the conclusion, we summarize the study's findings; present the practical implications for text teaching and understanding and give guidelines on RP abstract writing. Besides, we also point out the research's limitations and make some suggestions for further studies.