Background: Despite South Africa's huge investment in professional development, there is not a lot of research that shows that teachers change their teaching practices by attending formal interventions. This article focuses on English as First Additional Language (EFAL) and explores how one Grade 2 teacher changed her practice of oral language teaching while enrolled for an Advanced Certificate in Teaching (ACT) programme. The programme was offered to Foundation Phase teachers to improve their teaching knowledge and ultimately change their teaching practices. Objectives: The article explores one teacher's oral language teaching and use of teacher resources in a township school. The purpose is to understand how her instructional practices changed or did not change during the 18 months while she was enrolled with the ACT programme. Method: Data were collected over 18 months by observing six video-recorded literacy lessons, corroborated with interviews and field notes. These were analysed using principles of teaching EFAL espoused in the programme's intended curriculum. Results: The two exemplars offered demonstrate a gradual shift in teaching of oral language and use of resources by the end of the programme. The teacher code-switched appropriately most of the time and adequately used various strategies. She created opportunities to develop learners' oral vocabulary; however, explicit sentence building was absent. Findings further revealed that the teacher's engagement with many collaborative professional development activities, school support, together with her goal-achieving character, contributed to instructional changes. Conclusion: This study highlights that there are a number of other factors, such as the school context, the teacher's motivation and other informal learning opportunities that support teacher learning from a formal professional development intervention. It also advocates for more robust studies on how a teacher's practices change as a result of formal professional development opportunities.