Grammatical metaphor is a key resource in the evolution of language's semogenic potential: it allows for new meanings to be made by reconfiguring the relationship between lexicogrammar and semantics. In this talk, I propose a metafunctional perspective on its power. Grammatical metaphor is distinct from other semiotic shifts (such as transcategorisation or conversion) in that it draws on the stratified nature of language and involves a "constant decoupling and recoupling between the semantics and the lexicogrammar" (Halliday 2003: 253). It is therefore intimately tied to metaredundancy (Taverniers 2019), the dynamic mapping across levels that enables languages to stretch their meaning potential in context-sensitive ways.

This power is most visible in knowledge-based and technocratic discourse, where grammatical metaphor scaffolds abstraction, condensation and disciplinarity across ideational, interpersonal, and textual functions. But as Halliday reminds us, "with power comes responsibility" (2003: 269). In the final part of the talk, I explore the ethical and pedagogical implications: who gains access to this powerful resource, and how can it be taught? I argue for a socially engaged view of grammatical metaphor that foregrounds issues of access, appropriation, and linguistic agency in language education.

Halliday, M.A.K. 2003. Linguistics as metaphor. In: Halliday, M.A.K., On Language and Linguistics. Ed. by Jonathan Webster. Continuum. 248–270.

Taverniers, Miriam. 2019. Semantics. In: Thompson, Geoff, Wendy L. Bowcher, Lise Fontaine and Jennifer Yameng Liang (eds.) Cambridge Handbook of Systemic Functional Linguistics. Cambridge UP.