Complex sentence: John Jacob Philip Elkann (born April 1,1976) is an increasingly powerful global industrialist, grandson of the late Gianni Agnelli, and chosen heir to the automaker Fiat, which also owns the Alfa Romeo, Maserati, Ferrari, and Lancia marques.
Split into simpler sentences: John Jacob Philip Elkann (born April 1,1976) is an increasingly powerful global industrialist. He was the chosen heir of his grandfather Gianni Agnelli, and controls the automaker Fiat, which also owns the Alfa Romeo, Maserati, Ferrari, and Lancia marques.