Medium instruction refers to the use of a particular language as the primary medium through which educational content is taught, communicated, and assessed within an instructional setting [1]. The concept concerns the relationship between the language used for teaching and the transmission of subject knowledge, distinguishing the instructional language from the languages that may be taught as learning objectives themselves[1][2]. In language education and pedagogy, medium instruction encompasses decisions and practices regarding the selection and use of a language of instruction, including situations involving a first language, an additional language, or multiple languages as the medium for educational interaction [1][2].