EN
This paper shows the research on the history of language conducted by Krystyna Długosz-Kurczabowa. Her interest in etymology, the grammatical system of Polish, in particular word formation, is mentioned. The discussions on various issues related to the Bible, especially the Biblical onomastics and Biblicisms functioning in the old and contemporary language, as well as philological analyses of the oldest Polish written texts and research on the old and disappearing vocabulary are presented in more detail.