Tommy, home from school, is infatuated with his father's secretary, so he goes to their office to try to tell her.After quoting much poetry, he finds she loves another, causing more quotes.
As plots go, that's about it. However that does not do this film justice, like describing a Monty Python by saying "A man tries to return a dead parrot to a pet shop."
This is essentially a one-act stage play. The humor comes from the dialog. Edward Everett Horton, best known to our generation for his voice on the Fractured Fairy Tales,is incredibly funny. I would put him on the level of Groucho, while also being able to keep a real character.
For some reason it also reminded me of "The Importance of Being Ernest". I laughed very hard at this movie, and highly recommend it.