本研究对比了任务前和任务后形式聚焦对英语学习者学习被动语态的教学效果。127名初中生被分为任务前、任务后形式聚焦组和控制组。在任务前组，教师先引导学生聚焦被动语态的规则和使用，然后完成相关的交际活动任务。在任务后组，学生先进行与被动语态相关的交际活动任务，然后再聚焦被动语态的语法规则。控制组只完成测试。错误改正题和图片描述题的结果表明，任务前和任务后聚焦形式都能显著促进学生对被动语态的掌握，总体上任务前聚焦形式的效果更好。

This study compared the effects of pre-task and post-task focus on form on learners in learning the English passive voice. 127 EFL students from a Chinese junior middle school were assigned to three groups: pre-task group, post-task group and control group. In the pre-task group, students’ attention was first drawn to the rules and usage of passive voice and then to communicative activities and tasks. In the post-task group, communicative tasks were conducted first and then rules and usage of passive voice were covered. The control group only finished tests without receiving any instruction. Students’ acquisition of passive voice was measured through pretest, immediate posttest and delayed posttest of an error correction test and a picture description task. The results show that both pre-task and post-task focus on form can help learners in learning passive voice, and on the whole, pre-task focus on form has better effect than post-task focus on form.