Our first example is a project that we ourselves did on teaching children about the distinction between “-ion” and “-ian” endings. This distinction had become a test case for us. We had identified a simple and useful morphemic principle that had, we thought, the potential to help children conquer an aspect of spelling that normally causes them much trouble. The principle is that when the word is a noun that ends with a schwa vowel followed by an /n/ sound, the correct spelling for this ending is “-ian” if the noun refers to a person and “-ion” if it does not.