Here is the climax of the movie The Miracle Worker, with Anne Bancroft and Patty Duke:
The Miracle Worker tells the true story of Anne Sullivan (played by Bancroft) and Helen Keller (played by Duke), as recounted in Helen Keller’s autobiography The Story of My Life. In this scene, Helen suddenly grasps the idea that the sequences of hand gestures that Sullivan has been making stand for the names of things! Once Helen grasped this concept, she started racing around, demanding to know what other things were called. No ape has ever done that.