In this presentation, I will describe ‘interaction’ and its role in second language (L2) acquisition. I will outline different aspects of L2 interaction – including such aspects as comprehensible input and output, focus on form and also corrective feedback in its various guises (explicit and implicit) and what these interactional features can potentially contribute. I will focus in particular on the contribution interaction can make in supporting young (primary school aged) learners in their journey to gaining proficiency in another language – especially those learning English as a second language. Finally, I will explain the implication of the theory of interaction to teaching practice.