Complex sentence: Because of her close collaboration with Coper, and perhaps because they were both pre-war immigrants from German-speaking countries, Rie's pottery is often associated with Coper's, but while his work tended to be sculptural and abstract, Rie's remained predominantly functional.
Split into simpler sentences: Because of her close collaboration with Coper, and perhaps because they were both pre-war immigrants from German-speaking countries, Rie's pottery is often associated with Coper's. But while his work tended to be sculptural and abstract, Rie's remained predominantly functional.