Blurb:

This paper reports on a case study of a Chinese physics professor at a university in Shanghai, China. The purpose of the study is to investigate how his classroom explanations of causal meanings are realized through lexicogrammatical features in English as a foreign language. Data consist of one 60-minute lecture purposefully selected from a series of 20 hours of video recording of physics lectures compared to language from an English-medium physics textbook associated with the course. Instances of grammatical metaphor in causal explanations in the physics lecture were identified and analyzed using a functional approach. Drawing on an up-down metaphor, this paper uses the term ‘upward’ movement to refer to “functional recasts” from simpler towards more advanced (more grammatically metaphorical) wording, and ‘downward’ movement to describe functional recasts from more advanced towards simpler wording. Employing that metaphor combined with the Knowledge Framework (KF) revealed results which demonstrated that the Chinese physics professor used a range of lexicogrammar such as conjunctions, verbs, and nominalizations to assemble causal explanations that showed downward functional recasts to address the meaning and wording relationship in causal explanations. The study proposes implications for teacher training, specifically the training of International Teaching Assistants (ITAs) with the use of the KF heuristic.