The Department of the History of the Polish Language brings together experienced historians of language with diverse research interests, collectively encompassing a broad range of research areas, methodologies, and chronological scope—from the Middle Ages to the 20th century. The main research fields include:

• urban toponymy of Łódź, the language of the city, and Łódź regionalisms;
• the Polish language in Bible translations, including biblical onomastics;
• the legal variety of language, the development of legal terminology, and the influence of the Napoleonic Code on Polish legal terminology and legal language;
• gender linguistics;
• linguistic genology, particularly the development of journalistic and popular science genres in the 19th and 20th centuries;
• the language of writers (M. Rej, H. Sienkiewicz);
• Polish-Latin language contacts, especially the history of bilingual lexicography;
• linguistic customs in historical Poland;
• bilingualism in the history of the language;
• historical word formation;
• historical semantics and stylistics;
• the edition of historical texts.