Starting in 1871, he worked at the Kaunas Priest Seminary, and began teaching the Lithuanian language. He authored a grammar textbook in Lithuanian, "Mokslas lietuviškosios kalbos". After Baranauskas went to Sejny, he gained a considerable reputation by being able to preach in both Polish and Lithuanian. By 1880, after he realized that the ban of printing in the Lithuanian language would not be lifted, in spite of several unofficial promises by Tsarist authorities to do so, his desire to promote the Lithuanian language slowly declined. He never ceased to believe, that Lithuanian should be developed and expanded and until his death worked on a translation of the Bible into Lithuanian, and working 10–12 hours a day, succeeded to translate three fifths of the Old Testament.