Because there has been little research on focus on form during the post-task phase in task-based language teaching, this experimental study investigates the effects of task repetition after having directed learners' attention to form during the main task. The study comprises two interventions, where each consisted of a task with a focus on a particular language structure. Forty-eight ninth-grade students learning German as a foreign language were randomly assigned to two conditions: one group repeated a similar task (R); the other group did not (NR). The first intervention targeted the German dative case after a preposition; the second German comparatives. Pretests, immediate and delayed posttests measured metalinguistic knowledge, written and oral accuracy as well as oral fluency. Results showed that on written accuracy and metalinguistic knowledge, the R condition outperformed the NR condition on both structures. No significant differences between conditions were found on oral accuracy and fluency.