At the beginning of the 19th century (probably, also in the 18th century), in Calvinist writing greater attention started to be paid to the needs of the addressee – they dared to deviate more from the Polish tradition, and translations solely very closely related to the Polish source were no longer prepared. This is demonstrated by the results of the studies of Seanas Katechizmas (hereinafter referred to as SK). 1. The Calvinist work Seanas Katechizmas (1803), which was prepared for the press by Mykolas Cerauskas, is not homogeneous. The quotes from the Bible, hymns and prayers (except one), with minimal amendments, were taken from the catechism and primer Pradžios pamokslas (hereinafter referred to as PP) of 1680, from which the alphabet and examples of syllables as well as numbers were also taken. SK’s foreword and one prayer (“Małda Rita untra” SK 29–30) were prepared by Mykolas Cerauskas himself, which is evidenced by his other work, Kozonis padekawonies, coinciding features of spelling and language of the texts. 2. The main text, catechism (i.e. teaching the truths of faith), is of a slightly different spelling, language, and content than the texts of PP and those prepared by Cerauskas. Therefore, it was not prepared by Cerauskas. However, similarly to Cerauskas, the anonymous author was from the area of eastern Aukštaičiai (probably, Panevėžys) area (as demonstrated by part of the phonetic features, including reduced verb forms), but from a dialect that is rather farther to the west (this is reflected by some of the nasal reflexes). Unlike Cerauskas, the author managed to better overcome the peculiarities of his native dialect and to adhere to the norms of the middle variant (however, it is also true that more accurate spelling tradition, <ea> writing and other, were not taken over). 3. It is highly likely that in the 18th century, a significantly revised manuscript version of the catechism and primer was prepared. It departed from previously existing Lithuanian and Polish Calvinist catechisms (“Who are you?” type of catechism order). It was simplified even more than PP and was adapted to teach children. The main texts of faith ‒ the Lord’s Prayer, the Confession of Faith, the Decalogue, and the description of the sacraments ‒ departed from the versions of the 17th century very little but their order of presentation and the introductory part of the catechism were different. The author of this manuscript was probably a Calvinist priest who worked in a parish school. There is a lack of data to determine whether more catechism versions were developed at that time. 4. Despite its unusual structure, its difference from the catechisms of the “Who are you?” type, the manuscript catechism was included in the SK work of the early 19th century and, with a minor addition and other existing SK texts, was replicated under the title of the Shorter Catechism (Trumpas Katechizmas) in 1860s.