Advances in AI have enabled ESL learners to practice speaking through conversational systems. However, most tools rely on explicit correction, which can interrupt the conversation and undermine confidence. Grounded in second language acquisition and motivational psychology, we present AI Twin, a system that rephrases learner utterances into more fluent English and delivers them in the learner's voice. Embodying a more confident and proficient version of the learner, AI Twin reinforces motivation through alignment with their aspirational Ideal L2 Self. Also, its use of implicit feedback through rephrasing preserves conversational flow and fosters an emotionally supportive environment. In a within-subject study with 20 adult ESL learners, we compared AI Twin with explicit correction and a non-personalized rephrasing agent. Results show that AI Twin elicited higher emotional engagement, with participants describing the experience as more motivating. These findings highlight the potential of self-representative AI for personalized, psychologically grounded support in ESL learning.

翻译：人工智能的进步使得英语学习者能够通过对话系统练习口语。然而，大多数工具依赖显式纠错，这会打断对话并削弱学习者的信心。基于第二语言习得与动机心理学理论，我们提出了AI Twin系统，该系统将学习者的口语表达重新组织为更流利的英语，并以学习者本人的声音进行输出。AI Twin体现了学习者更自信、更精通语言的版本，通过与其理想的二语自我愿景保持一致来增强学习动机。此外，该系统通过重新组织表达提供隐性反馈，保持了对话的流畅性，并营造了情感支持性的学习环境。在一项针对20名成人英语学习者的组内研究中，我们将AI Twin与显式纠错系统及非个性化表达重组代理进行了比较。结果表明，AI Twin能引发更高的情感投入，参与者描述该体验更具激励性。这些发现凸显了自我表征人工智能在英语学习中提供个性化、基于心理学理论支持的潜力。