Complex sentence: Robert John Downey Jr. (born April 4,1965) is an American actor whose career has included critical and popular success in his youth, followed by a period of substance abuse and legal troubles, and a resurgence of commercial success in middle age.
Split into simpler sentences: Robert John Downey Jr. (born April 4,1965) is an American actor. His career has included critical and popular success in his youth, followed by a period of substance abuse and legal troubles, and a resurgence of commercial success in middle age.