Complex sentence: The 1989 Barcelona conference agreed that a key task was to put the issue of cities and their economic, political and social development onto the European agenda.Indeed, the founders suggested that major European cities could benefit from forming such an association.
Split into simpler sentences: The 1989 Barcelona conference agreed that a key task was to put the issue of cities and their economic, political and social development onto the European agenda. The founders suggested that major European cities could benefit from forming such an association.