Sociocultural and dialogic theories of education have identified the need to integrate both pedagogical content and language knowledge into teachers' professional development to promote effective interaction with students about subject content. In this intervention study, a meta-perspective on language was developed to understand how experienced teacher educators (N = 29) conceptualize ongoing language development in professional learning and teaching (referred to as language-developing learning in this study) as part of their pedagogical content knowledge. The data were analysed using content analysis. Language-developing learning was mainly conceived as teacher-oriented professional development. In this process, the language aspect was regarded not only as a tool that applies regulatory and explanatory language but also as a target that connects academic knowledge and interpersonally oriented language. The results increase our awareness of teacher educators' practical knowledge of academic and interpersonal language in specific disciplinary contexts of teacher professional development in higher education.