In recent years, daily practice at universities all over the world has involved online teaching due to the COVID-19 pandemic. Teaching online requires knowledge of new ways to engage with the students, but limited research concerning pedagogical aspects of online formats has been conducted to examine this further. Research shows that the teacher-student relationship is a critical factor in a student's development and learning in both traditional and online teaching. Limited research has examined teacher-student relationships in online teaching at universities further. In the present pilot study, a university mathematics teacher's digital relational competence is examined and visualized by using Halliday's Systematic Function Linguistics to explore what is said, the verbal language, and Burgoon and Hobbler's framework to visualize how it is said, i.e., the nonverbal language. Data were collected in autumn 2020 and involved a seminar with ten pre-service special educators in mathematics in Sweden; approximately 3 h of video-recorded material was collected. The result shows that the teacher's verbal language, such as the choice of questions, personal pronouns, and being personal, but also her nonverbal language, involving gestures, facial expressions, and paralanguage, are essential when building supportive teacher-student relationships in mathematics.