Children learning English as an additional language (EAL) are a diverse and growing group of pupils in England’s schools. Relative to their monolingual (ML) peers, these children tend to show lower receptive and expressive vocabulary knowledge in English, although interpretation of findings is limited by small and heterogeneous samples. In an effort to increase representativeness and power, the present study combined published and unpublished datasets from six cross-sectional and four longitudinal studies investigating the vocabulary development of 434 EAL learners and 342 ML peers (age range: 4;9–11;5) in 42 primary schools. Multilevel modelling confirmed previous findings of significantly lower English vocabulary scores of EAL learners and some degree of convergence in receptive but not expressive knowledge by the end of primary school. Evidence for narrowing of the gap in receptive knowledge was found only in datasets spanning a longer developmental period, hinting at the protracted nature of this convergence.