Student teachers learn in many ways, one of which can be through analysing teaching. For this, analytical frameworks that are accessible yet theoretically grounded are useful. The increasingly accepted characterisation of mathematics as a discourse has been developed into a fully-fledged theory—commognition—but the theory is hard for novices to access without additional operationalisation. In this paper, I explore theoretically whether a framework developed both to inform and analyse practice, Mathematics Discourse in Instruction (MDI), is compatible with commognition. Since MDI was developed in a particular context, I also consider the extent to which the framework is broadly applicable to different types of instructional organisation. I examine the application of MDI to two qualitatively different Swedish mathematics high school lessons. The results indicate high compatibility of MDI with commognition, making MDI a candidate for the analysis of mathematics lessons, which can be made available to student teachers. Application of the framework to the Swedish mathematics lessons suggested some limitations to the MDI framework’s wider applicability, wherefore some adjustments are suggested.