A Systemic Functional Approach To The Analysis Of Functions Of Context In Achieving Text Coherence

This thesis is an attempt to explore context's functions in achieving text coherence based on the framework of systemic functional linguistics. The aims for the study are to testify the operationality and practicability of applying Hallidayan context theory into the exploration of achieving text coherence.The theoretical bases include the theory of context of situation, the three metafunctions of language and their realization in the lexico-grammatical level: the Transitivity system, the Mood system and the Modality system, and the Theme-Rheme system in Halliday's functional linguistic theory.The semiotic components of context are field, tenor and mode which are systemically related to the functional components (ideational, interpersonal and textual) of the semantics: field to the ideational component, tenor to the interpersonal component and mode to the textual component. The ideational component is realized by transitivity system. The interpersonal component is realized by mood and modality. The textual component is shown structurally by thematic structure of sentences and non-structurally by cohesive devices. Thus the coherence of a text can be explained by analysis on the transitivity system, mood and modality, and thematic structure in a text.The transitivity analysis reveals that the choice of the transitivity of sentences should be fit in with the need of the text's field. In order to convey correct information to the readers and listeners, texts must represent the real world or fictional world with certain appropriate transitivity system.Mood and modality analyses reveal that different moods and modalities are used to convey different interpersonal meanings in concrete text. In order to establish and maintain interpersonal relationship, writers must correctly choose the mood and modality according to the tenor of the text.Theme-Rheme system analysis reveals that appropriate and consistent thematic structure can be easily recognized and accepted by the readers and listeners. It is needed to assign the text with the appropriate Theme according to the mode of the text.In this thesis, to make the language data analysis more reliable, valid and convincing, five typical texts are chosen from both written text and spoken text, not only from one type of them, as samples of analysis.In the conclusion, the thesis makes a summary of the major findings, presents some implications of the analysis to English language teaching, and points out originality, limitations of the research as well as some suggestions for further studies.