Complex sentence: The Pilcomayo River (Spanish: "Río Pilcomayo") is a river in the central parts of South America, longest western tributary of the Paraguay River, and its watershed extends across 270,000 km².
Split into simpler sentences: The Pilcomayo River (Spanish: "Río Pilcomayo") is a river in the central parts of South America. It is the longest western tributary of the Paraguay River, and its watershed extends across 270,000 km².