What pattern may there be of semantic difference between basic nouns and basic verbs? At first glance, relative permanence seems related. Consider for example: “The duck flew away.” The duck was almost definitely already in existence before it flew away, and it was almost definitely still in existence after it flew away. Only in a story with magic could it be otherwise. That is (again, unless there’s magic, e.g. a wizard casting a spell that causes a duck to appear in existence only long enough to fly away before then disappearing from existence): For any given thing in space that the basic noun “duck” is a true label or description of, the basic verb “fly” is a true label or description of that thing at fewer moments in time. Temporally speaking, there’s a whole-part relationship: The label/description “duck” is always true of that thing, meaning that being a duck is something true of every moment in time of its existence, and the label/description “fly” is sometimes true.

However, that proposed distinction doesn’t work because not only is the relationship between nouns like “duck” and verbs like “fly” a temporal whole-part relationship, but the relationship between nouns like “duck” and adjectives like “small” is also like that. That is: A duck is still a duck whether it starts or stops flying, whether it starts or stops being small. The nominal quality of being a duck is relatively permanent, and both the verbal and adjectival qualities of flying and being small are relatively impermanent.

With all of that said, my proposed distinction is as follows (without using the terms “verb,” “noun,” and “adjective”):

1. There are the always-true labels (e.g., “duck”).
2. There are the sometimes-true labels that go back and forth between being true and false more freely (e.g., “fly”).
3. And there are the sometimes-true labels that go back and forth between being true and false less freely (e.g., “small”).