Complex sentence: For much of the 18th and 19th centuries, Novi Sad was the largest Serb-inhabited city in the world; reformer of the Serbian language, Vuk Stefanović Karadžić, wrote in 1817 that Novi Sad was the "largest Serb municipality in the world".
Split into simpler sentences: For much of the 18th and 19th centuries, Novi Sad was the largest city in the world populated by ethnic Serbs. The reformer of the Serbian language, Vuk Stefanović Karadžić, wrote in 1817 that Novi Sad is the "largest Serb municipality in the world".