This study is situated in a newly emerging EMI setting in China where an Anglophone high school curriculum is taught by predominantly foreign teachers through English to local Chinese students. These teachers are termed ‘monolingual teachers’ in the sense that they cannot use the students’ L1 as a resource in their teaching should they wish to, as opposed to the typical bilingual teachers commonly explored in the existing EMI literature. Through quantitative and qualitative analysis of 30 video-recorded EMI science lessons taught by 15 monolingual teachers, this study identified and explored the language-focused-episodes (LFEs) where students’ attention was explicitly diverted from the content plane to the language plane. The study found very limited explicit language instruction, with non-technical vocabulary being the main type of LFEs, and only a narrow range of grammatical features being attended to. The implications for this lack of focus on language are discussed in the context of monolingual teachers but also with reference to the potential for bilingual teachers to use both L1 and L2 for LFEs.