Slovak, a language of the West Slavic subgroup of Slavic languages, is the official language of Slovakia; Slovak is closely related to the Czech language. Hungarian is also widely spoken. In July 1994 a law was passed allowing the use of Hungarian as the official language in areas of Slovakia where at least 20 percent of residents speak Hungarian. However, this was retracted by a subsequent law, passed in November 1995, which makes Slovak the only language that can be used in the civil service, on road signs, and in advertisements.