Complex sentence: An early and outspoken opponent of the Nazis, Anni Frind curtailed her activities in Germany upon the rise of Hitler, retiring from professional singing at the outbreak of the second world war and later marrying.
Split into simpler sentences: An early and outspoken opponent of the Nazis, she curtailed her activities in Germany upon the rise of Hitler. She retired from professional singing at the outbreak of the second world war, later marrying.