Complex sentence: Mackenzie "Big Mac" Chalker played by Charles Dale, first appeared on 24 November 2007 as a porter until October 2013, when he applied to become an emergency care assistant.
Split into simpler sentences: Mackenzie "Big Mac" Chalker played by Charles Dale first appeared on 24 November 2007. He was a porter until October 2013, when he applied to become an emergency care assistant.