original_query: What changes did Karadžić make to the Slavonic-Serbian written language in the early 19th century?
query: What changes did Vuk Karadžić make to the Slavonic-Serbian written language in the early 19th century?
answer: Vuk Karadžić modernized the Serbian literary language, basing it on the Eastern Herzegovina dialect he spoke.  He standardized the Serbian Cyrillic alphabet using strict phonemic principles, abandoning many words connected to the Orthodox church and Russian Church Slavonic loanwords found in the earlier written language. This distanced the written language from Church Slavonic and brought it closer to common folk speech.