Vowel insertion in the middle of a word can be observed in the history of the Slavic languages, which had a preference for open syllables in medieval times. An example of this is the Proto-Slavic form 'town', in which the East Slavic languages inserted an epenthetic copy vowel to open the closed syllable, resulting in (), which became () in modern Russian and Ukrainian. Other Slavic languages used metathesis for the vowel and the syllable-final consonant, producing *"grodŭ" in this case, as seen in Polish , Old Church Slavonic градъ "gradŭ", Serbo-Croatian and Czech .