Complex sentence: Gregorio Paltrinieri (born 5 September 1994) is an Italian competitive swimmer, World Long course and Short course champion and two-time European champion in the 1500 m freestyle event at the 2012 and 2014 European Aquatics Championships.
Split into simpler sentences: Gregorio Paltrinieri (born 5 September 1994) is an Italian competitive swimmer. He is the world long course and short course champion and two-time European long course champion in the 1500 m freestyle event at the 2012 and 2014 European Aquatics Championships.