The research examines the binary opposition of “good” and “evil” in the English and French languages within the context of foreign language teaching. The aim is to analyze these concepts’ lexical-semantic and cultural aspects and explore their implications for foreign language learners. The study adopts a comparative approach, considering the similarities and differences in representing “good” and “evil” in the two distantly related languages. The analysis focuses on the semantic structure and distribution of lexical units associated with these concepts and the cultural connotations embedded in their usage. The research focuses on how the binary opposition of “good” and “evil” impacts language learners’ understanding of the target culture and their ability to communicate effectively in the foreign language. The latter gain a deeper appreciation of the target culture’s moral values and social dynamics by examining the cultural meanings and connotations associated with these oppositions. The findings highlight the asymmetry of lexical units within the lexical-semantic groups of “good” and “evil”, revealing discrepancies in the number and distribution of words and their meanings. Antonymy and enantiosemy are identified as regularities in forming vocabulary, denoting good and evil in the compared languages. These linguistic tools enable learners to express contrasting concepts and enhance their linguistic and intercultural awareness. Incorporating the binary opposition of “good” and “evil” in foreign language teaching can promote a deeper understanding of the target culture’s values, norms, and worldview. Learners become more sensitive to cultural aspects and better equipped to navigate intercultural interactions by unravelling the underlying cultural codes embedded in language.