The current study set out to examine to what degree age of acquisition (AOA), defined as a learner’s first intensive exposure to a second language (L2) environment, mediates the final state of postpubertal, spoken vocabulary attainment. In Study 1, spontaneous speech samples were elicited from experienced Japanese users of English (n = 41) using storytelling and interview tasks. The samples were analyzed using a range of corpus- and rater-based lexical measures and compared to the speech of inexperienced Japanese speakers (n = 40) and native speakers of English (n = 10). The results showed that most experienced L2 learners tended to demonstrate nativelike proficiency for relatively easy lexical dimensions of speech (i.e., richness), but that AOA appeared to play a key role in predicting the ultimate attainment of relatively difficult lexical dimensions (i.e., appropriateness). In Study 2, the findings were successfully replicated with experienced L1 Polish users of English (n = 50).

目前的研究旨在探讨习得年龄 (AOA)（定义为学习者首次密集接触第二语言 (L2) 环境）在多大程度上介导青春期后口语词汇获得的最终状态。在研究 1 中，通过讲故事和访谈任务，从经验丰富的日本英语使用者 ( n = 41) 中提取了自发语音样本。使用一系列基于语料库和基于评分者的词汇测量对样本进行分析，并与缺乏经验的日语使用者 ( n = 40) 和英语母语人士 ( n = 10) 的语音进行比较。结果表明，大多数经验丰富的二语学习者倾向于在相对简单的言语维度（即丰富性）方面表现出类似母语的熟练程度，但 AOA 似乎在预测相对困难的词汇维度（即适当性）的最终实现方面发挥着关键作用。在研究 2 中，结果被经验丰富的 L1 波兰语英语使用者 ( n = 50) 成功复制。