the Croatian part of Syrmia) The fourth group of dialects is often not considered a separate group, but a subgroup of Central and Western Slovak dialects (see e.g. Štolc, 1968), but it is currently undergoing changes due to contact with surrounding languages (Serbo-Croatian, Romanian, and Hungarian) and long-time geographical separation from Slovakia (see the studies in Zborník Spolku vojvodinských slovakistov, e.g. Dudok, 1993). The dialect groups differ mostly in phonology, vocabulary, and tonal inflection. Syntactic differences are minor. Central Slovak forms the basis of the present-day standard language. Not all dialects are fully mutually intelligible. It may be difficult for an inhabitant of the western Slovakia to understand a dialect from eastern Slovakia and the other way around. The dialects are fragmented geographically, separated by numerous mountain ranges. The first three groups already existed in the 10th century. All of them are spoken by the Slovaks outside Slovakia, and central and western dialects form the basis of the lowland dialects (see above). The western dialects contain features common with the Moravian dialects in the Czech Republic, the southern central dialects contain a few features common with South Slavic languages, and the eastern dialects a few features common with Polish and the East Slavonic languages (cf. Štolc, 1994). Lowland dialects share some words and areal features with the languages surrounding them (Serbo-Croatian, Hungarian, and Romanian). Regulation Standard Slovak () is defined by an Act of Parliament on the State Language of the Slovak Republic (language law). According to this law, Ministry of Culture approves and publishes the codified form of Slovak based on the judgment of specialised Slovak linguistic institutes and specialists in the area of the state language. This is traditionally Ľudovit Štúr Institute of Linguistics, which is part of the Slovak Academy of Sciences. In practice, Ministry of Culture publishes a document that specifies authoritative reference books for standard Slovak usage, which is called '' (codification handbook). Current regulation was published on 15 March 2021. There are four such publications: '', 2013; (grammar rules) '', 2020; (dictionary) '', 2009; (pronunciation) '', 1966; (morphology) See also Slovak orthography Slovak phonology Slovak declension List of language regulators for a list of languages with a regulated standard variety References Bibliography Dudok, D. (1993) Vznik a charakter slovenských nárečí v juhoslovanskej Vojvodine [The emergence and character of the Slovak dialects in Yugoslav Vojvodina]. Zborník spolku vojvodinských slovakistov 15. Nový Sad: Spolok vojvodinských slovakistov,