Complex sentence: He is best known for his work on "The Sketch Show" on ITV which won a BAFTA award and also played the role of Tom, the owner of the Leaky Cauldron, in "Harry Potter and the Prisoner of Azkaban".
Split into simpler sentences: He is best known for his work on "The Sketch Show" on ITV, which won a BAFTA award. He also played the role of Tom (the owner of the Leaky Cauldron) in "Harry Potter and the Prisoner of Azkaban".