A Corpus-based Study Of Modality Across Genres From The Perspective Of Probabilistic Grammar

Modality is an important means in the realization of the interpersonal metafunction of language, and research in modality takes up an important part in the field of Systemic Functional Linguistics. Researches in modality are mainly conducted within the theoretical framework of interpersonal metafunction, discussing about the features of modality in some specific genres or comparative study on modality in two types of genres. In recent years, corpus-based approach has been applied in modality studies, which mainly focus on some central modal verbs. So far, corpus-based study of modality from the perspective of probabilistic grammar is rarely found.Probabilistic grammar attaches great importance to the systemic and probabilistic nature of language. In the view of probabilistic grammar, probability is an inherent feature of language system; and probability in system is instantiated as frequency in text. With the purpose to have a more systemic understanding of modality, this study intends to explore the probabilistic profile of modality system across genres based on probabilistic grammar in Systemic Functional Linguistics. By adopting the corpus-based approach and selecting news discourse, academic discourse and fiction discourse from FLOB corpus as data, this study intends to explore the probabilistic profile of modality system in the three genres so as to reveal the correlation of modality system, interpersonal metafunction and genre variation. Major findings are as follows:Firstly, modality system is manifested as a skewed type across news discourse, academic discourse and fiction discourse. In terms of modality type, the three genres share the same unmarked modality-modalization. In the sub-systems of type, news discourse and fiction discourse are both unmarked with usuality and inclination while academic discourse is unmarked with probability and obligation. In terms of orientation, all of the three genres are unmarked with implicit subjective. In terms of value, news discourse is unmarked with median value; academic discourse is unmarked with low value; and fiction discourse shows roughly even probability. Secondly, based on statistic analysis, it is found that the choices of options in modality system can be interpreted as different interpersonal metafunction in different genres, which shows that the choices of options in modality system are resulted from the interpersonal metafunction of specific genre. Thirdly, different probabilistic profiles of modality system across three given genres have revealed the correlation of language system and genre variation, and the resetting of probability in modality system is one of the factors that result in genre variation.The study of modality system from the perspective of probabilistic grammar has presented a much more systemic picture of modality system in the three given genres. It is hoped that such systemic and probabilistic description of modality may provide some insights for researchers and learners on better understanding the probabilistic profile of modality system and its correlation to genre, which may raise genre-sensitive consciousness in language use. It is also hoped that the study may provide some implications for foreign language teaching and translation studies related to English modality.