Register-based distribution of expressions of modality in COCA

This research scrutinizes expressions of modality at both word and clause ranks. Expressions at the former rank encompass modal verbal operators, modal adjuncts, and modal nominalizations, and expressions at the latter rank encompass ‘explicit subjective’ orientation such as I think and ‘explicit objective’ orientation, such as it is possible. These latter expressions are designated as interpersonal metaphors of modality within the framework proposed by Halliday. Previous studies delimited the distribution of expressions of modality either at word rank or at clause rank; in addition, they undertheorized the relationship between this distribution of modality and formality of registers because the register is testified to be an influential factor in the distribution of expressions of modality. This study, drawing on such statistical methods as variation analysis and correlation analysis, explored the distribution of expressions of modality at both word and clause ranks across registers with different degrees of formality by employing the Corpus of Contemporary American English (COCA). The findings are summarized as follows. First, registers in COCA employ expressions of modality with low and/or median values to judge the proposition at issue for the purpose of entertaining other varying voices. Second, in more formal registers, language users seem to prefer modal nominalizations to modal verbal operators and modal adjuncts at word rank, and ‘explicit objective’ orientation to ‘explicit subjective’ orientation at clause rank. In doing so, they could efficiently conceal the commentators’ subjective meaning, and thus, the objectivity of propositions is highlighted. This study will shed light on the full understanding of the distribution of expressions of modality across registers and the application of such theory as interpersonal metaphor of modality in SFL.