William Zinsser denounces journalists who form nouns out of adjectives. People are not "notables" or "greats," he says. Teaching at the Columbia University Graduate School of Journalism, Zinsser recommends respecting words and their shades of meaning. He says adjectives are unnecessary when they state the obvious, as in "yellow daffodils." One way to classify adjectives is into common, demonstrative and proper. Irregular adjectives can be viewed as another type. Adjectives most often precede the noun they describe.
The common adjective is just a "plain old" adjective -- "big," for example. Common adjectives may refer to a singular or plural noun. Common adjectives have three forms -- positive, comparative and superlative. "Big" is the positive form; "bigger" is the comparative form, used to compare two things; "biggest" is the superlative form, used to compare three or more things. When a common adjective has more than one syllable, like "excellent," the comparative is formed by addition of the word "more," and the superlative is formed by addition of the word "most" -- "more excellent," "most excellent."
The demonstrative adjectives are "this," "that," "these" and "those." Demonstrative adjectives refer to singular or plural nouns. They tell "which one" -- for example, "Do you want to watch this movie or that movie?" The same words become demonstrative pronouns when they substitute for nouns -- for example, "Do you want to watch this or that?"
Proper adjectives are based on proper nouns, or names, and are capitalized. The adjective forms of the proper nouns China, Spain, Japan and Texas are "Chinese," "Spanish," "Japanese" and "Texas." In the case of Texas, the proper adjective is the same as the proper noun, although "Texan" is also a proper adjective. Another form of proper adjective is one that describes or names a group of people or a specific place. "Native" is not a proper noun so is usually not capitalized, but "Native American" names a specific group of people, so "Native" is capitalized. Another example is "Red" in "Red Sea."
Irregular adjectives do not follow the rules; they have their own comparative and superlative forms, which must be memorized. The positive adjectives "bad," good" and "many" have the comparative forms "worse," "better" and "more" and the superlative forms "worst," "best" and "most." Adjectives that do not have comparative or superlative forms at all include "perfect," "unique," "universal," "wrong" and "final."