This paper presents a rational argument based on examples of real language to make the case that lay definitions of parts-of-speech are more complex than commercial language pedagogy appreciates. Put simply, school grammars are misleading. They tend to pick the most convenient words for explanation and categorize them as if there were few or no variants within that category, when in reality, however, variation is the norm. Word class categories as presented in typical textbook illustration function as a handicap to future learning. I thus argue two points in this paper. First, that the definitions of lexical categories ought to be made in the form of respecting distinct linguistic dimensions and not in oversimplified and misleading one- dimensional categories which must be unlearned in order for learners to begin actually learning about how languages function. Secondly, a proper theory that radically separates the representation of linguistic expressions in the various grammatical components must be adopted for pedagogy to develop. I illustrate these points with examples drawn from English and Japanese.