Complex sentence: Started in Sweden in 2003, World Storytelling Day is a global celebration of the art of oral storytelling, celebrated every year on the first day of spring in the northern hemisphere, the first day of autumn in the southern.
Split into simpler sentences: Started in Sweden in 2003, World Storytelling Day is a global celebration of the art of oral storytelling. It is celebrated every year on the first day of spring in the northern hemisphere, the first day of autumn in the southern.