Complex sentence: Thelma Ritter is the most nominated in the Best Supporting Actress category, with six, while in the Best Supporting Actor category four actors have each received four nominations, Walter Brennan, Arthur Kennedy, Nicholson and Claude Rains.
Split into simpler sentences: Thelma Ritter is the most nominated in the Best Supporting Actress category with six, while in the Best Supporting Actor category four actors have each received four nominations. They are Walter Brennan, Arthur Kennedy, Nicholson and Claude Rains.