Complex sentence: Gary Adams, portrayed by Samuel Kane, was a man who was posing as a 19 year old boy, talking to 14 year old Sarah Platt (Tina O'Brien) through an internet chatroom.
Split into simpler sentences: Gary Adams, portrayed by Samuel Kane, was a man who was part of a storyline for 14 year old Sarah Platt (Tina O'Brien). He was posing as a 19 year old boy, talking to Sarah through an internet chatroom.