Science can be a difficult subject for EAL (English as an Additional Language) learners to master, mainly because of the prominent role that language plays in the acquisition of scientific concepts. Language is essential to science because it is the means by which we envisage and communicate new ideas. Teaching this new language to pupils involves being able to explain the real meaning by acting as interpreters. EAL learners find it both conceptually and linguistically demanding to understand the complexities of the new scientific vocabulary that teachers present to them. In the first of two articles, Mark Hainsworth, a Senior Lecturer in Education at the University of Chester, shares some of the pedagogy and strategies that he has used to help EAL learners with their understanding of science concepts. One of the key strategies that he has found to have the most impact on EAL learners' conceptual understanding is contextualising key scientific vocabulary using visualisation techniques.