Lag effects in grammar learning: A desirable difficulties perspective

Abstract This paper examined lag effects in the learning of second language (L2) grammar. Moreover, following Desirable Difficulty Framework for L2 practice, present study investigated whether could be explained by other sources difficulty. Using digital flashcards, 117 English learners (aged 10–18) learned two grammatical structures over different sessions at a 1-day or 7-day intersession interval (ISI). Learners’ performance was analyzed retention intervals (RIs) 7 and 28 days, respectively. Linguistic difficulty compared examining structures, while learner-related comparing who differed terms age, proficiency, time required to complete training. Results showed no main effect ISI, RI, small but significant ISI × RI interaction. age did not interact with RI. However, longer lags led significantly higher scores faster shorter promoted slower lower proficiency. The findings provide some support its potential explain effects.