Complex sentence: The Seattle SuperSonics (commonly known as the Sonics) were a professional basketball team based in Seattle, Washington, that played in the Pacific and Northwest Divisions of the National Basketball Association (NBA) from 1967 until 2008.
Split into simpler sentences: The Seattle SuperSonics (commonly known as the Sonics) were a professional basketball team based in Seattle, Washington. They played in the Pacific and Northwest Divisions of the National Basketball Association (NBA) from 1967 until 2008.