This longitudinal research presents case studies of three English as a foreign language (EFL) student teachers showing their development regarding target language (TL) use, taking into account both the amount of TL use and the classroom situations the TL is used in. Additionally, the factors that influence their TL use are discussed. The data consist of four questionnaires, three classroom observations, and a written reflection on TL use. Results show that -- similar to experienced teachers -- these student teachers used the TL more in senior than in junior classes and mainly in linguistically predictable situations. On the other hand, the amount of their TL use was high, especially in senior classes, compared to earlier studies in the Dutch context. The student teachers displayed different developmental patterns concerning TL use during teacher education: two of them increased their use of English, mainly in junior classes; TL use of the other student remained stable. Teacher education appeared to mediate TL use one year after graduation for two students. TL use had changed after finishing teacher education but no coherent developments could be discerned.