Complex sentence: Pietro Belluschi (August 18,1899--February 14,1994) was a Portland, Oregon architect, a leader of the Modern Movement in architecture, and responsible for the design of over one thousand buildings.
Split into simpler sentences: Pietro Belluschi (August 18 1899--February 14 1994) was a Portland, Oregon architect. He was a leader of the Modern Movement in architecture, and was responsible for the design of over one thousand buildings.