The non-equivalent lexical units, that is, the scientific definition of realias, the problems of their classification, the opinions of scientists and specialists who have conducted research in this field, the difficulties that arise when translating them into English, and the methods of overcoming these difficulties, using examples, have been clarified in the article. The novel “Bygone Days” by A. Kadiri has been chosen as the object of the research, which is considered the crown of Uzbek romanticism, where the non-equivalent lexical units were used. These lexical unites were scientifically described, classified, and scientific and theoretical conclusions and proposals for translating them into English were presented based on examples using comparative, mixed and correlational research methods. The scientific approaches and views of foreign and domestic scientists and specialists who conducted research in this field have also been analyzed. As a result, the authorʼs scientific and theoretical proposals for translating various realities used in literary translation into English were presented, and methods for achieving equivalence and adequacy in reflecting non-equivalent lexicons in the translation text were revealed. The translations of the work into English by I. Tukhtasinov, O. Muminov, A. Khamidov, K. Ermakova, and M. Reese are analysed from an artistic and stylistic perspective. The principles of expressive and full expression of the lexicon without alternatives in literary translation are examined from a linguistic and translation studies perspective, translation options are compared, and the author offers alternative translation variants.