Are the words as important as the concepts? Using pedagogical language knowledge to expand analysis of mathematics teaching with linguistically diverse students

We examine how two ninth grade mathematics teachers in a linguistically diverse school used general-everyday and discipline-specific language, along with language access strategies, during a lesson on linear rates of change. We use the socioculturally based framework of "pedagogical language knowledge" (PLK) to understand and unpack the teachers' use of general-everyday and discipline-specific language. We argue that the teachers' language use corresponded to concrete instances of PLK in action in the multilingual mathematics classrooms examined. We then discuss the potential of PLK as a lens for examining the pedagogical and linguistic choices of secondary mathematics teachers in linguistically diverse mathematics classrooms in light of foundational works in language and mathematics education in linguistically diverse contexts.