The co-director of the 1938 film, Anthony Asquith, had seen Mrs. Campbell in the 1920 revival of" Pygmalion" and noticed that she spoke the line, "It's my belief "as how" they done the old woman in." He knew "as how" was not in Shaw's text, but he felt it added color and rhythm to Eliza's speech, and liked to think that Mrs. Campbell had ad libbed it herself. Eighteen years later he added it to Wendy Hiller's line in the film.