This study investigates the acoustic characteristics of the English intervocalic lateral /l/ as pronounced by American, South Korean, and North Korean speakers. The study focuses on the distinctive articulatory and acoustic properties and explores phonetic adaptation and pronunciation differences among these groups, with a particular emphasis on the influence of Korean phonological systems on the production of the English /l/. The research reveals that while South and North Korean speakers display similar phonetic patterns when articulating the Korean intervocalic /l/, distinct variations emerge in their pronunciation of the English intervocalic /l/. Notably, North Korean speakers typically produce a singular clear /l/, akin to that observed in American speakers. This suggests that since North Korean speakers articulate a clear [l] in Korean word-initial positions, the pronunciation of the English intervocalic /l/ is influenced by their phonetic inventory, aligning with the motor theory of speech perception. In contrast, South Korean speakers predominantly produce a geminate [ll], reflecting an adaptive strategy under phonological constraints that restrict Korean word-initial /l/ productions. This phonological parsing demonstrates the interaction that is influenced by native phonological rules.