Language acquisition is a complex cognitive and social process in which the learner’s first language (L1), commonly known as the mother tongue, plays a crucial role. In multilingual contexts like India, learners often acquire English as a second or foreign language (ESL/EFL), and their mother tongue significantly influences pronunciation, grammar, vocabulary, and discourse patterns. This paper examines the influence of the mother tongue on the acquisition of the English language, highlighting both positive and negative effects. Using a qualitative-descriptive methodology supported by secondary sources, the study reviews year-wise literature to understand how L1 transfer affects second language learning. The findings reveal that while mother tongue interference may cause errors in phonology and syntax, strategic use of L1 can facilitate comprehension, confidence, and cognitive development. The study underscores the pedagogical significance of integrating mother tongue support in English language teaching for effective and inclusive learning.