Complex sentence: They play their home games at the Cardiff City Stadium, after moving from Ninian Park in 2009, and have long-standing rivalries with nearby clubs Swansea City, known as the South Wales derby, and Bristol City, known as the Severnside derby.
Split into simpler sentences: They play their home games at the Cardiff City Stadium, after moving from Ninian Park in 2009. They have long-standing rivalries with nearby clubs Swansea City, known as the South Wales derby, and Bristol City, known as the Severnside derby.