In the Project for Enhancing Effective Learning (PEEL) teachers have been working at promoting metacognition for 25 years in a collaborative action research project. A group of PEEL teachers has recently taken metacognition a step further by developing new ways of making explicit sense of teaching and learning. They have systematically built, with their students, a shared language for learning and regularly share their pedagogical purposes with their students. In this paper we outline four kinds of knowledge that we believe are necessary for enhanced metacognition.