When migrating to a new country, there is often a need to learn a new language and find a job. In Sweden, and to meet this need, a type of work-integrated language learning program, called combination courses, with the idea that students learn the language and a vocation simultaneously, has been initiated. In this article, such a combination course, centering around the Swedish language and cleaning skills, and providing apprenticeship workplace placements for the students, is studied. Using boundary crossing as a lens to analyze ethnographic observational data, consisting of 65 hours of observations, this case study analyses the boundary practices created by one workplace supervisor. The results show that the supervisor establishes a boundary crossing practice that comprises around two hours of theoretical studies for the student each day he spends on the practice, and, over time, how this boundary practice becomes increasingly like schoolwork. This boundary practice provides the student with abundant language learning affordances. It emphasizes both oral and written communication, giving the student the opportunity to develop both during the placement. The experiences gained from this work-integrated language learning program provide valuable insights into the supervising practice involved when students are expected to learn both language and vocational skills simultaneously.