Complex sentence: Veteran actor John Ritter voiced Clifford in all episodes, this was originally done by Brent Titcomb in the 1988 and the early 1990s.
Split into simpler sentences: Veteran actor John Ritter voiced Clifford in all episodes. This was originally done by Brent Titcomb in the series that debuted in 1988 and ran into the early 1990s.