This thesis delves into the intricate process of acquiring polysemous nouns in English as a Foreign Language (EFL) and explores the pivotal role of learners' native language (L1) in shaping their meaning construal of these lexical items. Polysemous nouns, characterized by having multiple related meanings, pose a unique challenge for EFL learners, as they require a nuanced understanding of contextual usage and semantic nuances. Drawing on the assertion that most natural languages are characterized by their plasticity, this study examines the intricate process EFL learners undergo in discerning and internalizing the diverse meanings associated with polysemous nouns. The research investigates the potential transfer of meanings from Croatian to English and explores the distinctions between metonymical and metaphorical extensions of meaning, aiming to unravel their varying effects on the acquisition process. Through a comprehensive examination of the data, this research seeks to contribute to the understanding of the role of L1, Croatian, in shaping the meaning construal of polysemous nouns among EFL learners. The outcomes may inform language educators about potential challenges and effective instructional strategies for enhancing vocabulary acquisition in an EFL context, ultimately contributing to the optimization of language learning methodologies.