This study compared the effects of task repetition only (TR), task repetition with grammatizing (TR+GR), and grammatization with no task repetition (GR) on 94 EFL learners' oral task performances. Participants' productions were measured both in terms of complexity, accuracy, and fluency as well as receptive knowledge (measured by an error correction test) and productive knowledge (measured by a sentence-level oral production test) development. Immediately after performing a narrative task, the TR+GR and GR learners were required to restore the target structure, namely the English regular past tense, which had been deleted in a grammatized text. Learners in the TR group received no grammatization, and only the TR+GR and TR groups repeated the same task twice. Results revealed that although both TR conditions led to enhanced receptive knowledge, the TR+GR performed better than the TR in fostering learners' receptive knowledge and improving accuracy and productive knowledge at a delayed posttest. The GR group improved their receptive knowledge in the immediate posttest, but this improvement tailed off in the delayed posttest. Lastly, the TR+GR group could also improve the complexity and accuracy of their narrative task performances--albeit at the expense of fluency.