Study On The Expressivity Of Deontic Modality In English Discourse

This thesis aims to study the expressivity of deontic modality in English discourse, that is, tostudy the extent of modal meanings that conveyed by deontic modality in English discourse.The expressivity of deontic modality is embodied by modality value and modal orientation.Generally speaking, the expressivity of inclination deontic modality is often in accordancewith modality value and that of obligative deontic modality is usually with modal orientation.This thesis selects altogether forty pieces of typical discourse as corpus, including twentypolitical speeches on the2012presidential election in the United States and twenty businessEnglish letters and negotiation conversations. Based on the theoretical framework ofHalliday’s Systemic-Functional Grammar, this thesis studies the expressivity of deonticmodality in these two types of discourse with both quantitative and qualitative analysismethods. Also it makes a contrastive analysis of the similarities and differences of theexpressivity of deontic modality between these two types of discourse and presents anexplanation for that from the perspectives of discourse style and pragmatic effect. The resultsindicate that the expressivity of deontic modality in political speeches is comparatively higherthan that in business English. Besides, the contrastive analysis has revealed the expressivitysimilarities of obligative deontic modality and expressivity differences of inclination deonticmodality between the two types of discourse. On the other hand, the comparatively detailedanalysis of the expressivity of deontic modality in political speeches and business English,has not only testified the practical feasibility of Systemic-Functional Grammar in specificdiscourse analysis, but also further deepened our understanding of the allocation andpragmatic meaning of deontic modality in them. Moreover, it is helpful for English learnersto know how to properly express commitment, permission, responsibility and obligation, andultimately achieve their communicative purposes and intentions in different types ofdiscourse, thus enhancing communicative competence.