Complex sentence: However, Calabrian Greek has never experienced an extensive growth period during its history, and it has only ever been used in basic day-to-day communications, without ever playing a significant role in the fields of administration, literature, or ecclesiastical matters.
Split into simpler sentences: However, Calabrian Greek has never experienced an extensive growth period during its history. It has ever been used only in basic day-to-day communications without ever playing a significant role in the fields of administration, literature or ecclesiastical matters.