Shell nouns as grammatical metaphor in knowledge construal: Variation across science and engineering discourse

Abstract This article proposes a novel treatment of cataphoric shell nouns (SNs) as instances of grammatical metaphor serving to reconstruct human experience into knowledge through the discipline-specific construal of different transitivity processes. Based on a two-million-word corpus of research articles in physics and aeronautic engineering, we investigated the sub-disciplinary variation in the use of SNs between science and engineering. While the two disciplines are found to demonstrate similar preferences for SN items evidenced by a large set of common SNs, the empirical study has uncovered significant differences. Firstly, physics favours finite clauses while aeronautic engineering favours non-finite clauses as preferred SN complementation types. Secondly, physics primarily chooses identifying relational processes to characterise fact-like propositions while aeronautic engineering tends to prefer attributive relational processes to express dynamic modality and mental processes of volition to highlight desirability of potential activities under specific conditions. Thirdly, physics resorts to verbal processes of assertion to argue for the discovery of discipline-internal theories while aeronautic engineering relies on material processes to construe laboratory-based activities. These findings reveal the fundamental differences between science and engineering as two discourse types and demonstrate SNs as significant manifestations of cognitive construals underpinning linguistic variations across the two registers.