The study investigates the linguistic phenomenon of At-Tamyiiz in Quranic Arabic and its complex translation into English, focusing on the interplay between grammatical structure and conceptual meaning. Drawing on a hybrid theoretical framework that integrates Halliday’s Systemic Functional Linguistics (SFL) and Sandra Halverson’s Cognitive Translation Theory (CTT), it analyzes selected Quranic verses containing At-Tamyiiz and compares their translations by Pickthall, Yusuf Ali, and Abdel-Haleem. The analysis categorizes the main types of At-Tamyiiz, such as Tamyiiz al-Mufrad, Tamyiiz al-Jumla, and constructions following numbers, measures, and verbs of praise or blame. It examines their ideational, interpersonal, and textual functions in Qur’anic discourse. The study also identifies cognitive shifts and “gravitational pulls” that lead translators toward entrenched patterns in the target language. Findings show that At-Tamyiiz often undergoes semantic expansion, lexical substitution, or rhetorical reframing in English because there is no direct morphosyntactic equivalent. Translators often compensate by explicitation, metaphor adjustment, or clause restructuring. The study argues that effective translation of At-Tamyiiz requires detailed linguistic awareness and sensitivity to the cognitive frames of target readers. By combining functional and cognitive perspectives, the research offers a dual-level model to explain both grammatical function and conceptual processing in Qur’anic translation.