Vocabulary acquisition is a central component of second language learning. While there have been advancements in our understanding of the factors contributing to vocabulary acquisition in L2 students, it is still unclear how language aptitude is associated with the effects of task involvement load in this process. This study investigates the effects of task involvement load on incidental vocabulary learning and their association with language aptitude. One hundred and forty-four participants were assigned to five groups. All groups finished reading a passage and completed tasks that had different involvement loads. A pretest and two posttests adapted from Paribakht and Wesche’s (TESOL Can J 11:9–29, 1993) Vocabulary Knowledge Scale (VKS) were employed to assess learners’ development of the target vocabulary items. The LLAMA test (Meara, in: In_lognostics, Retrieved from February 14, 2017, from https://www.lognostics.co.uk/tools/llama, 2005) was administered to measure participants’ language aptitude. We found that, in the immediate posttest, the Gap-fill (with search) group showed superiority over the Reading (no need) and Reading (with need) groups, while the Sentence-writing group significantly outperformed the other four groups. In the delayed posttest, both the Gap-fill (with search) group and the Sentence-writing group significantly outperformed the other three groups. Our study also reveals a moderate correlation between language aptitude and vocabulary learning.

词汇习得是第二语言学习的核心组成部分。虽然我们对 L2 学生词汇习得的影响因素的理解有所进步，但仍不清楚语言能力如何与此过程中的任务参与负荷的影响相关联。本研究调查了任务参与负荷对偶然词汇学习的影响及其与语言能力的关联。一百四十四名参与者被分配到五个小组。所有小组都完成了一篇文章并完成了具有不同参与负荷的任务。采用 Paribakht 和 Wesche (TESOL Can J 11:9–29, 1993) 词汇知识量表 (VKS) 改编的前测和两个后测来评估学习者对目标词汇项的发展。LLAMA 测试（Meara，在：In_lognostics，检索自 2017 年 2 月 14 日，来自 https://www.lognostics.co.uk/tools/llama，2005）用于测量参与者的语言能力。我们发现，在紧接的后测中，Gap-fill（与搜索）组表现出优于阅读（不需要）和阅读（有需要）组的优势，而写句子组的表现明显优于其他四组。在延迟后测中，Gap-fill (with search ) 组和 Sentence-writing 组均显着优于其他三组。我们的研究还揭示了语言能力和词汇学习之间的适度相关性。