This study examines the multifaceted challenges faced by learners acquiring English as a second language (ESL), focusing on cognitive, social, and pedagogical barriers that impede language proficiency development. Through a comprehensive analysis of current literature and empirical research, this paper identifies key obstacles including phonological interference, syntactic complexity, cultural identity negotiation, and institutional inadequacies. The research employs a mixed-methods approach, analyzing both quantitative data from language assessment scores and qualitative interviews with ESL learners across diverse linguistic backgrounds. Findings reveal that learners face significant challenges in mastering English phonology due to L1 interference, struggle with complex grammatical structures absent in their native languages, and encounter socio-cultural barriers that affect motivation and identity formation. The study concludes that effective ESL instruction must address these multidimensional challenges through culturally responsive pedagogy, individualized learning approaches, and comprehensive support systems that acknowledge learners' linguistic and cultural diversity.