Perhaps the most famous line in Madame Bovary occurs when the narrator likens human speech to "a cracked kettle." The inadequacies of language is another theme that runs throughout the novel. How does this affect the novel as a whole?
Flaubert uses Emma's desperate search for an almost unreal kind of romance as a conduit to infuse a language which is equally dissonant with reality. This occurs in chapter 12 during one of Emma's attempts to get Rodolphe to feel just as wildly needful of Emma as she is of him.
Oh no; no one else pleases you. There are some more beautiful, but I love you best. I know how to love best. I am your servant, your concubine! You are my king, my idol! You are good, you are beautiful, you are clever, you are strong!"
All of these words are all too familiar to Rodolphe, who compares Madame Bovary to all of his other mistresses. This would coincide with Flaubert's quote
Humanspeech is like a cracked tin kettle, on which we hammer out tunes to make bears dance when we long to move the stars.