There are certain words I will always remember after having a seventh grade English teacher (Mrs. Linda Miller, Fort Jr. High School) who was really into vocabulary. One of these words is "malapropism." I looked it up just to be sure I was remembering correctly. Merriam-Webster defines it as "the usually unintentionally humorous misuse or distortion of a word or phrase; especially: the use of a word sounding somewhat like the one intended but ludicrously wrong in the context."
Tobin astounds us everyday with his increasing mastery of our language. He talks in paragraphs now and frequently will start a conversation by saying, "I have an idea, Mama." He also uses "because" fluidly, although he can be a bit circular in his reasoning: "I like chocolate milk because it's my favorite!" However, he does mix up words sometimes--his own special set of malapropisms, if you will. "Alligator/elevator" as well as "chicken/kitchen" are classics. Recently, he adopted a more perplexing one: "envelope/peppermint."
Tobin also insists on calling tomatoes potatoes. The other day at lunch I was trying to explain that he was eating a tomato and that potatoes are what he helps Daddy cut up and roast when we have burgers. Tobin looked at me and said, "Mama, you say tomato, I say potato." And that was that.