Complex sentence: The Novi Sad Agreement was an attempt by twenty five Serbian, Croatian and Montenegrin writers, linguists and intellectuals to build unity across the ethnic and linguistic divisions within Yugoslavia, and created the modern Serbo-Croatian language.
Split into simpler sentences: The Novi Sad Agreement was the crucible in which the modern Serbo-Croatian language was born. The Agreement was an attempt by twenty five Serbian, Croatian and Montenegrin writers, linguists and intellectuals to build unity across the ethnic and linguistic divisions within Yugoslavia, and created the modern Serbo-Croatian language.