Croatia
Croatian is the official language of Croatia, and became the 24th official language of the European Union upon its accession in 2013. Minority languages are in official use in local government units where more than a third of population consists of national minorities or where local legislation defines so. Those languages are Czech, Hungarian, Italian, Ruthenian, Serbian, and Slovak.
According to the 2011 Census, 95.6% of citizens of Croatia declared Croatian as their native language, 1.2% declared Serbian as their native language, while no other language is represented in Croatia by more than 0.5% of native speakers among population of Croatia. Croatian is a member of the South Slavic languages of Slavic languages group, and is written using the Latin alphabet. There are three major dialects spoken on the territory of Croatia, with standard Croatian based on the Shtokavian dialect. The Chakavian and Kajkavian dialects are distinguished by their lexicon, phonology, and syntax.
Croatian replaced Latin as the official language of the Croatian government in the 19th century. In Yugoslavia, from 1972 to 1989, the language was constitutionally designated as "Croatian literary language". It was the result of the resistance to "Serbo-Croatian" in the form of a Declaration on the Status and Name of the Croatian Literary Language and Croatian Spring. Croatians are protective of their Croatian language from foreign influences and are known for Croatian linguistic purism, as the language was under constant change and threats imposed by previous rulers (i.e. Austrian German, Hungarian, Italian, and Turkish words were changed and altered to Slavic looking or sounding ones).
Serbo-Croatian
In the mid-19th century, Serbian (led by self-taught writer and folklorist Vuk Stefanović Karadžić) and most Croatian writers and linguists (represented by the Illyrian movement and led by Ljudevit Gaj and Đuro Daničić), proposed the use of the most widespread dialect, Shtokavian, as the base for their common standard language. Karadžić standardised the Serbian Cyrillic alphabet, and Gaj and Daničić standardized the Croatian Latin alphabet, on the basis of vernacular speech phonemes and the principle of phonological spelling. In 1850 Serbian and Croatian writers and linguists signed the Vienna Literary Agreement, declaring their intention to create a unified standard. Thus a complex bi-variant language appeared, which the Serbs officially called "Serbo-Croatian" or "Serbian or Croatian" and the Croats "Croato-Serbian", or "Croatian or Serbian". Yet, in practice, the variants of the conceived common literary language served as different literary variants, chiefly differing in lexical inventory and stylistic devices. The common phrase describing this situation was that Serbo-Croatian or "Croatian or Serbian" was a single language. During the Austro-Hungarian occupation of Bosnia and Herzegovina, the language of all three nations was called "Bosnian" until the death of administrator von Kállay in 1907, at which point the name was changed to "Serbo-Croatian".