Complex sentence: He was born at Walton Hospital, in Liverpool but his family moved to London when he was 2 years old and he attended the Hampton Grammar School in Richmond upon Thames where Paul Samwell-Smith was a fellow pupil.
Split into simpler sentences: He was born at Walton Hospital in Liverpool, but his family moved to London when he was two years old. He attended the Hampton Grammar School in Richmond upon Thames where Paul Samwell-Smith was a fellow pupil.