walks and impress ~ describe ~ description, but where the final result is still a word that needs to be remembered in the lexicon. In contrast, inflectional morphology is usually freely predictable, so the lexicon (like a printed dictionary) doesn't need to store all the regular forms, though it does need to have entries for irregular forms like sang. On the other hand, some entities larger than a traditional word also need to be stored. While compounding is sometimes transparent, so that we know what a wild horse is just from the two components, there are huge numbers of expressions tha...