This study investigated the differences in linguistic complexity between different types of English users, including native speakers (NS), English as a foreign language (EFL) learners, and English as a second language (ESL) learners in terms of Kolmogorov complexity. Furthermore, we explored how first language backgrounds affect linguistic complexity. Our dataset contains 2272 argumentative essays produced by English NSs and upper-intermediate learners from four ESL and six EFL countries/regions. Results showed that significant differences existed between the writings of NS, EFL, and ESL regarding overall and syntactic complexity. Specifically, the rank of overall complexity (NS > ESL > EFL) indicates that learners from countries/regions with higher exposure to English tend to produce overall more complex writings. Concerning syntactic complexity, EFL learners produce the most complex writings, while NS produces the least complex, indicating that essays written by EFL learners contain the most fixed word order patterns. In contrast, no significant difference was detected in morphological complexity among the NS, ESL, and EFL groups, suggesting that native and upper-intermediate non-NSs exhibit a similar range of morphological forms in their writings. Additionally, our results showed a larger effect of first language backgrounds over English speaker types on linguistic complexity, thus informing teachers to implement targeted writing instructions for learners from different countries.

中文翻译：

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说话者类型和母语背景对学习者写作语言复杂性的影响

本研究调查了不同类型英语用户（包括母语者（NS）、英语作为外语（EFL）学习者和英语作为第二语言（ESL）学习者）之间在柯尔莫哥洛夫复杂性方面的语言复杂性差异。此外，我们还探讨了第一语言背景如何影响语言复杂性。我们的数据集包含来自四个 ESL 和 6 个 EFL 国家/地区的英语 NS 和中高级学习者撰写的 2272 篇议论文。结果表明，NS、EFL 和 ESL 的写作在整体和句法复杂性方面存在显着差异。具体来说，整体复杂性的排名（NS>ESL>EFL）表明，来自英语接触程度较高的国家/地区的学习者往往会写出总体上更复杂的作品。就句法复杂性而言，EFL 学习者写出的文章最复杂，而 NS 写出的文章最不复杂，这表明 EFL 学习者写的文章包含最固定的词序模式。相比之下，NS、ESL 和 EFL 组之间的形态复杂性没有显着差异，这表明母语和中高级非 NS 在其写作中表现出相似的形态形式。此外，我们的结果显示，第一语言背景比英语使用者类型对语言复杂性的影响更大，从而告知教师为来自不同国家的学习者实施有针对性的写作指导。