Various approaches have emerged in educational research through the analysis of how teachers support students in their text creation process. This study examines the subject-specific knowledge that primary and secondary school teachers utilise when reviewing and providing feedback on draft texts written by their students, considering the impact of teaching experience and the national context. A total of 90 teachers from Chile and Spain took part in the study, which was designed to reflect differences in educational stage and years of experience. A comparative quantitative design was used to apply error identification tests in four dimensions: spelling, rhetoric, text and grammar. The results revealed a higher detection rate for spelling and grammar errors, in contrast to a lower level of attention given to rhetorical organisation and textual properties. Significant differences were identified based on teaching experience, with the intermediate group (6–15 years) performing best and a downward trend among more veteran teachers. Comparisons between countries revealed complementary profiles, albeit with similar overall values. In conclusion, there is a need to strengthen teachers’ linguistic and didactic training in order to balance attention between the formal and macro-textual aspects of writing.