I get a special thrill in watching language-use develop in my 2 and a half year old son. I particularly enjoy discovering his grasp of concepts like opposites and how he applies them in a logically consistent fashion but which defy the often illogic nature of the English language.
One of the latest was the statement: "Wake up," which was followed by a pause, then a smile and the words: "Sleep down."
It does make sense. If a person wakes up, then when they sleep they most logically must sleep down. Here I've been calling myself a writer, a manipulator of words and phrases, yet in the past year or so as my son has been developing his own approach to the English language, I think I've learned more than in the previous three decades.