Complex sentence: Robert G. Wahlberg (born December 18,1967) is an American actor who has appeared in films such as "Southie", "Mystic River", and "The Departed".
Split into simpler sentences: Robert G. Wahlberg (born December 18,1967) is an American actor. He has appeared in such films as "Southie", "Mystic River", and "The Departed".