While they offer convenient formalisms and better packaging mechanisms, even object-oriented models have a distinctive conceptual and expressive bias. For conceptual models, "thinking outside the box" takes on a whole new meaning. In fact, our thinking does exceed the rectangular borders of our object models. We must remember that there are concepts other than simple nouns (objects) and verbs (methods). Our language offers a rich panoply of descriptive qualities and case relations, if only we can find meaningful use for them in our models. The following table provides a brief summary of this richness.
| Class | Subclass | Indication |
| adjective | descriptive adjective | quality, instantiation, differentiation (classification) |
| limiting adjective | quantity, limit, index, factor | |
| graduated adjective | positive, comparative, superlative | |
| verb | transitive verb | action, relationship |
| intransitive verb | action | |
| noun | common noun | person (role), place (space/time), object (class) |
| proper noun | identification (name) | |
| pronoun | reference, possession | |
| preposition | predicative preposition | participation |
| possessive preposition | possession | |
| conjunction | coordinate conjunction | inclusion, exclusion, conclusion, contrast |
| subordinate conjunction | reason, degree, concession, condition, manner, place, purpose, time | |
| correlative conjunction | inclusion (both-and), exclusion (either-or, neither-nor), conclusion (if-then) | |
| adverb | descriptive adverb | affirmation, negation, doubt, reason, degree, manner, number, time, place, location, direction |
| interrogative adverb | choice (whether), reason (why), manner (how), time (when), place (where), origin (whence), direction (whither) | |
| demonstrative adverb | choice (thus, then, hence), time (now, then, hence), place (here, there), direction (hither, thither, hence, thence) | |
| conjunctive adverb | inclusion |