An Analysis of Modal Adverbs of Certainty in Linguistic Academic Discourse

Abstract

Abundant interpersonal meanings are reflected in academic discourses. As an important means of performing interpersonal function, modality has drawn attention in the field of academic discourse. Based on Systemic Functional Linguistics (SFL) and with the help of LancsBox 5.0, this study identifies modal adverbs of certainty (MACs) in the 60 papers published in The Modern Language Journal and classifies them into 4 types according to MAC Theory introduced by Simon-Vandenbergen and Aijmer, including epistemic, expectation, evidential and speech act MACs. The data are used to research on the features in the use of MACs in linguistic academic discourse and the factors which influence the features in the use of MACs. The research results show that epistemic, expectation and evidential MACs are used frequently, which occur 87, 85, 65 times respectively, while speech act MACs are not used frequently, occurring 22 times in total. Specifically, under the 4 classifications, the frequency of polysemous MACs and MACs which have various significant forms of manifestation is relatively high. At the same time, MACs occur frequently because their meanings are appropriate to the features of academic discourse. Therefore, this study believes that the features in the use of MACs are mainly influenced by polysemy, form of manifestation and stylistic feature. This study validates MAC Theory for analyzing linguistic academic discourse from the theoretical points of view as well as helps readers learn about the features in the use of MACs and apply them into actual academic reading and writing from the practical points of view.