In the 17th and 18th centuries Protestant intellectuals in the Slovak lands of the Kingdom of Hungary predominantly used the Bohemian language. This was a result of the fact that the Lutheran Reformation in the Slovak lands was carried out by means of the Bohemian language and because of the migration of Bohemians to Slovak lands in the 17th century. These Slovak Lutherans called their language Bibličtina, since it was a reworking of the language used in the Kralice Bible. During the Counter-Reformation, Jesuits introduced a Slovak codification based on dialects spoken in the western region of the Slovak lands. This development added a linguistic element to the Catholic-Lutheran schism as Lutherans held on to their use of the Bohemian language. The Catholic priest Anton Bernolák (1762–1813) developed a codification of the Slovak language based on the work of the Jesuits. While focusing on the dialect spoken in the western Slovak lands, he also included numerous elements of the Central Slovak dialect. Bernolák published the first Slovak grammar (Grammatica Slavica) in 1790. Bernolák’s codification was prominently used for the first time in Juraj Fándly’s (1750–1811) Dúverná zmlúva medzi mňíchom a ďáblom (“An intimate treaty between a monk and the Devil”). The priest-poet Ján Hollý (1785–1849) also used Bernolák’s codification for his own works and for his translations of major classical works (notably his rendition of the Aeneid). Bernolák’s dictionary Slowár Slowenskí, Češko-Laťinsko-Ňemecko-Uherskí (“A Slovak to Czech-Latin-German-Hungarian dictionary”) was published posthumously between 1825-27 by the priest Juraj Palkovič (1763–1835). Palkovič also published a first Slovak translation of the Bible in Bernolák’s codification between 1829 and 1832. Still, Bernolák’s followers failed to gather a substantial group of supporters beyond the Catholic clergy.

In 1803 a department of Czech-Slovak languages and literature was established at the Protestant Lyceum in Pressburg (now Bratislava) by another Juraj Palkovič (1769–1850), who became its first professor. Palkovič not only lectured on the Czech and Slovak language, but also on Serbian, Polish and Russian. František Palacký (1798–1876), Jan Kollár (1793–1852) and Ľudovít Štúr (1815–1856) were students at this lyceum. In 1829 the Pressburg students established Společnost Česko-Slovanská (Czech-Slovak Society), which aimed to educate students on the Czech and Slovak language and literature. The activities of the society peaked between 1835-37, under the leadership of Ľudovít Štúr, when it had over 120 members and published an almanac, poetry and organized scientific and political meetings.

From the 1820s onward, the Slovak Lutheran clergyman-poet Ján Kollár actively advocated a merger between the Czech and Slovak languages. Kollár had established his fame with his sonnet-cycle Slávy dcera (“Sláva’s daughter”), which he published from 1824 onwards in the Bibličtina codification. In 1836, Kollar published his essay O literarnéj vzájemnosti mezi kmeny a nářečími slavskými (“On the literary reciprocity between the various tribes and dialects of the Slavic nation”), in which he expressed his views on the linguistic unity between the Slavic languages. To strengthen the cultural position of the Slavs he proposed to unite the numerous dialects within four major branches: Russian, Polish, Illyrian and Czechoslovak. The Slovak historian and philologist Pavel Josef Šafárik in his Geschichte der slavischen Literatur und Sprache nach allen Mundarten of 1826 also advocated the linguistic unification of Bohemia, Moravia and the Slovak lands. Both Kollár and Šafárik published Herder-inspired folk-song collections – Šafárik’s Pjsne swetske lidu slowenského w Uhřjch (“Secular songs of the Slovaks in Hungary”, 1823) and Kollár’s Národnie zpiewanky, čili pjsne swetské Slowakuw w Uhrách (“Folk songs or wordly songs of Slovaks in Hungary”, 1834-35); both were published in Bibličtina and as such were far removed from spoken usage.

The idea of a common Czechoslovak language was met with disapproval by Magyar politicians as they saw Pan-Slavism as a threat to the position of the Magyars in the Hungarian Kingdom. The Illyrian movement was mistrusted for the same reason. To establish a position for Slovak within the Hungarian Kingdom, the young clergyman Ľudovít Štúr created a Slovak codification independent from a Czech or Czechoslovak agenda. This would allow Slovaks to oppose the centralist and homogenizing Magyarization policy without buying into Pan-Slavism. On the basis of Bernolák’s work, Štúr together with Michal Miloslav Hodža (1811–1870) and Jozef Miloslav Hurban (1817–1886) developed a codification based on the Central Slovak dialects; it followed spoken usage far more closely than the Bibličtina. This also gave their work a far greater popular and social outreach.

Štúr, Hodza and Hurban published their work in 1846 in Nárečja slovenskuo alebo potreba písaňja v tomto nárečí (“The Slovak dialect or the necessity to write in this dialect”) and Nauka reči slovenskej (“The theory of the Slovak language”). The latter work reads as a protest against Kollár’s Czechoslovak agenda. Štúr argued that the four languages as proposed by Kollár would leave no room for the literary tradition of the smaller Slavic languages. Štúr proposed his own idea of a Slavic language tree comprising eleven branches: Russian, “Little Russian” (Ukrainian/Ruthenian), Bulgarian, Serbian, Croatian, Slovenian, Polish, Czech, Upper Sorbian, Lower Sorbian and Slovak. Štúr also supported his argument for an independent Slovak language, alongside Czech, by arguing that Slovak, having been less exposed to German influences, was a more purely Slavic language. From 1844 Štúr was allowed to publish a newspaper in the Slovak language, the Slovenské národné noviny, which later included a literary supplement called Orol tatranski.

In 1851, representatives of the Catholic and Lutheran denominations agreed on a single codification; it was a compromise between the Štúr and Bernolák standards. The Austro-Hungarian Ausgleich of 1867, which gave more power to the government in Pest, unleashed an intense Magyarization policy which halted any further development of the Slovak language and culture in the 19th century.