Drawing on an adapted formative assessment framework, this study investigated classroom practices across 99 lessons taught by 50 teachers in eight high schools across the Western Cape and Eastern Cape. Across diverse school resourcing levels and class sizes, we found that instruction was overwhelmingly dominated by a communalised pedagogy—characterized by teacher exposition, whole-class low-level recall questioning, with minimal individualised engagement. Notably, variations in formative assessment were far more pronounced across school subjects than across school types or class size.