Researchers worldwide agree that teachers should use formative assessment to support student learning. This study investigates how formative assessment strategies are used by teachers in an SFI classroom for adult learners in a medium-sized municipality in Sweden. The findings show that most teachers regularly use some form of formative assessment, with feedback, peer assessment at the group level, and recurring text revision being the most popular activities. A thematic analysis of the interviews reveals that teachers believe formative assessment can be an effective tool to motivate adult learners to take responsibility for their own learning, despite the perceived shortcomings of the education system. This aligns with previous research in the field, suggesting that the use of formative assessment combined with teachers' positive attitudes can help students achieve the best possible learning outcomes. Some suggestions are made on how to further support teachers in implementing the formative assessment strategies they perceive as most effective in their future work.