This article presents the phonetic and inflection linguistic changes in the three editions of Krzysztof Kluk’s The trees, garden herbs and gardens (edit. 1777, 1797, 1808). The first part of the analysis focuses on those changes that are consistent with the evaluation of the Polish nationwide standardized language at the turn of the eighteenth and nineteenth centuries. The second part of the article presents linguistic changes where the modern and correct forms are changed into the older one, consistent with the north-eastern Polish language of the Eastern Borderlands. Ascertaining why the editors of Kluk’s book used the older linguistic forms instead of the correct forms, leads to attempts to determine the standard linguistic norms in the Piarists’ printing house during the very short period at the turn of the eighteenth and the nineteenth centuries.