There are fast-paced comedies, and then there’s His Girl Friday, where Cary Grant, Rosalind Russell and the rest of the cast ad-lib over each other to get a word in edgewise. The film is based on the play The Front Page, in which a newspaper editor tries to keep his star reporter from defecting with one last great story. The switch here is that the role of the reporter was changed to a woman, the editor’s ex-wife.
An IMDb poster said that director Howard Hawks thought of the gender switch at a dinner party where a woman spoke the dialogue from The Front Page. Wikipedia says it occurred during casting after Hawks’ secretary read the reporter’s lines. However it happened, the added level of conflict turned a good play into a great film. The American Film Institute’s 100 Years…100 Laughs ranked this as the 19th funniest movie of the century, and it fits well as the second-highest ranked movie in the Internet Archive Top 100.