The learning of modern languages in primary school (PL) was recently promoted to statutory status in the curriculum of England and Wales, but practice remains patchy. Low PL capacity amongst primary school teachers and constraints on curricular time persist. Viewed through the lenses of policy, learning theory and context, current PL practice can be problematised to find solutions. Neurobiological evidence attests to how the young brain learns language, particularly its heightened sensitivity to language phonology. Additionally, policy documents' currently eclectic approach is discussed. Activity Theory's framework is employed to interconnect such contextual and theoretical factors. The evidence suggests that without optimising the PL environment, learning may be at least ineffective, or at worst, detrimental to pupils' future language learning.