A practical english grammar - Vyssaja skola 1978
Chapter 14 - Adjectives
Sound symbols
Adjectives are the third major class of words in English, after nouns and verbs. They have traditionally been defined as almost any word that modifies a noun, but modern grammarians restrict this definition somewhat. Some call adjectives only those words that can be compared (big, bigger), designating everything else that resembles such words but does not share their inflection (beautiful, for instance), as “adjectivals.” In this book, we are going to use a definition that is based on syntax, or the
way adjectives fit into sentence patterns. An adjective, by our definition, is any word that can be used both (1) between a noun determiner and a noun and (2) as a modifier of the subject after a linking verb:
the old man
The man is old.
some difficult lessons
The lessons are difficult.
Most adjectives have the function of assigning s.ome quality to the noun: heavy, useful, bold, narrow, clever. Such qualities may be present in greater or lesser degree, and therefore the nouns that possess them can be compared. This is done by modifying the adjective in a way that is called the comparison of adjectives.
Other adjectives put nouns in categories: French, British, naval, economic. In their ordinary meanings, these adjectives can not be compared. A person or thing is either French or not French, though we may sometimes extend the original meaning and say “She seems more French than her husband.” In that case, we have turned French into a descriptive rather than a categorizing adjective. We will see that these two kinds of adjectives behave differently in sentences. (See Chapter 17.)