What are some examples of how hyperbole and colloquial expressions contribute to the humor of "Why I Live at the P.O."?

The plot alone would not be enough to make Welty's story humorous; the dialogue and style of her narrative is essential to the story.  Welty uses many Southern idioms in order to show a truly eccentric Mississippi clan. The dialogue in the story is informal and realistic, filled with sentence fragments, slang, and words spelled to emphasize the way Welty’s characters talk, "Papa Daddy l-a - y - s down his knife and fork." Welty also uses familiar Southern expressions such as ‘‘dizzy as a witch,’’ ‘‘kiss my foot,’’ and ‘‘Miss Priss” to give her story more flavor. In terms of hyperbole, the narrator, Sister, is very melodramatic.  She sees the smallest events and insults suffered at the hands of her family as the end of the world, particularly when it comes to her sister Stella Rondo: ‘‘She’s always had anything in the world she wanted and then she’d throw it away.” Sister’s ability to overstate the mundane makes Welty’s story a hilarious interpretation of life in the South.