In 1836, Croatia was admitted as the reform of Vuk , such event has motivated the desire to unite with the Croats, Serbs. In result of this reform, the Croats began to use shtokavsky dialect instead chakavskogo. However, they are the alphabet, they used Latin, which was kind of a model of the Czech alphabet. On the Croatian side, the introduction of Reform in life engaged in L. Guy. Agreement on the adoption of a uniform for the Serbian and Croatian literary form was adopted in Vienna in 1850. Obstacle to the unity of languages were different versions of pronunciation sound yat, which belonged to the Old Slavic sounds.

This difference is reflected in the literary form of the Croatian version of the same in the two languages of literary form. When in 20 century in the city began to move in rural areas, in literary form of the language appeared local and regional dialects. So, the old form of the language by the time lag in the vocabulary and in syntax. Needed a new language reform. And in 1954, adopted new rules according to which affirmed the unity of the three national languages: Serbian, Croatian and Montenegrin. Along with this, the linguistic norms of Croatian language, the foundation was laid that the Zagreb dialect and language norms Serbian language, built on the Belgrade dialect, according to the accepted convention were part of a unified literary language. This language is called "Serbo-Croatian" or "the Croat-Serb" and both names in this case were correct and equal.