This article describes the application of systemic functional linguistics (Halliday & Matthiesen, 2004; Martin & Rose, 2005) to the teaching of science in a 4th grade classroom in the United States. Drawing on different data sources, including classroom lessons and planning meetings between a teacher educator and a teacher, a framework for working with mainstream content-area teachers is mapped out, based on work on the teaching/learning cycle (Rothery, 1994) and the notion of scaffolding (Hammond, 2001) applied to teacher education.