This study examines via qualitative content analysis how teachers use and teach formulas in physics lessons, focusing on linguistic varieties (special language, educational language, and everyday language) and their classification according to a level model of formula verbalization. The research design allows a detailed reconstruction of how teachers convey formulas linguistically in class and which content-related and methodological priorities they set in doing so. A total of 10 physics teachers in Saxony schools were observed over a period of five to ten lessons per teacher and their language audio-recorded. The relevant parts of the lessons were transcribed and analyzed with qualitative content analysis according to Kuckartz (2016). The resulting category system provides the first systematic description of teachers’ use of language when dealing with formulas in the classroom and identifies deficits in teaching structural mathematical-physical connections. The results contribute to deriving implications for teacher training, in particular for promoting understanding-oriented formula teaching.