Original: Guess Who's Coming to Dinner is a  drama film starring Spencer Tracy, Sidney Poitier and Katharine Hepburn, and featuring Hepburn's niece Katharine Houghton.
Simplified: Guess Who's Coming to Dinner is a 1967 comedy-drama film starring Spencer Tracy, Katharine Hepburn, Sidney Poitier, and Katharine Houghton.