The EuroSLA (2021) conference was sadly delayed one year by COVID-19, then made virtual the next, preventing us from gathering in beautiful Barcelona. However, at least this meant that there is a usable recording that allows dense summary. My plenary reflects my most up-to-date thinking on why second language learners have particular problems learning L2 morphosyntax. Usage-based approaches to the acquisition of L2 morphology. (52 minutes)