Complex sentence: Ernestus Johannes Christiaan Greven (September 8,1885--March 8,1924) was a Dutch athlete, who competed at the 1908 Summer Olympics in London.
Split into simpler sentences: Ernestus Johannes Christiaan Greven (September 8,1885-March 8,1924) was a Dutch athlete. He competed at the 1908 Summer Olympics in London.