Complex sentence: Tamborrada of Donostia (in basque Donostiako Danborrada) every year on 20 January (the feast of Saint Sebastian), the people of the city of San Sebastián, (Spain) celebrate a festival known as the "Tamborrada".
Split into simpler sentences: Tamborrada of Donostia (in basque Donostiako Danborrada) occurs every year on January 20th (the feast of Saint Sebastian). The people of the city of San Sebastián, (Spain) celebrate a festival known as the "Tamborrada".