Subject English is a knowledge structure that is hard to discern for many students and even teachers. The abstractions that underpin analysis and interpretation of texts can be fuzzy, even invisible. Furthermore, traditional knowledge is inadequate when it comes to websites, graphic novels and films. What guiding abstractions are relevant in studies of digital multimedia and canonical works such as novels? If we are building a knowledge structure for a twenty-first century discipline, can concepts embedded in the curriculum be rendered not just visible but accessible? This challenge is one faced by teachers at all levels of schooling. This paper draws on findings from a small research project investigating secondary teachers' work with textual concepts in New South Wales and Australian Capital Territory schools. It builds on case study data from ten teachers who incorporated concepts like 'representation', 'point of view' and 'character' into units of work they implemented with Year 9/10 students in 2019. We interviewed teachers about the affordances and challenges of textual concepts and explored what they had learned with key students. Early analysis of the data reveals significant shifts in the understandings of some teachers and students and lines of inquiry for future research. Most striking are findings related to conditions necessary to creation of deep knowledge in English, including: active support from school leaders; willingness of teachers to grapple with challenging concepts and use them to design units of work; links between key concepts; essential questions and assessment tasks; access to professional dialogue; and contexts that encourage transfer of learning by students. The implications of our findings for future-oriented research in English are reviewed in the conclusions.