This article presents a story of practice regarding how a primary school addressed the issue of supporting English as an additional language or dialect (EAL/D) learners to communicate and reason in mathematics. A shared understanding across the school uncovered teachers have a critical role in supporting EAL/D learners and their acquisition and use of mathematical language. The authors hope this paper might be helpful for teachers and school leaders who believe that each teacher is responsible to know each learner. This includes knowing their phase of English language acquisition, to give them the opportunity to learn, understand and develop the disposition to use mathematics.