The character Ů (ů; a Latin U with overring, or in Czech Republic) is a grapheme in the Czech language preserved for historic reasons, which identifies a vowel shift. For example, the word for "horse" used to be written "kóň", which evolved, along with pronunciation, into "kuoň". Ultimately, the vowel disappeared completely, and the "uo" evolved into "ů", modern form "kůň". The letter "ů" now has the same pronunciation as the letter "ú" (long ), but changes to a short "o" when a word is morphed (e.g. nom. "kůň" → gen. "koně", nom. "dům" → gen. "domu"), thus showing the historical evolution of the language. "Ů" cannot occur in initial position. However, "ú" occurs almost exclusively in initial position or at the beginning of a word root in a compound. These characters are used also in Steuer's Silesian alphabet. The pronunciation has prevailed in some Moravian dialects, as well as in the Slovak language, which uses the letter ô instead of ů.