In the remainder of this book, apart from the last chapter, which is about sentences, the chapters are based upon the major word classes of English: noun, verb and adjective. What is often regarded as a fourth major class, the adverb, will be discussed in the chapter on sentences (see pp. 74–7). Major classes, unlike minor ones, contain very large numbers of words, so many that it would hardly be possible to make a complete list of them. When a new word is added to the language, it is added to one of these classes (e.g. hooha, sauna, gungy, skinhead…). Since it takes a time for a new word to become accepted (if indeed it ever is), the total inventory of words must always be somewhat indeterminate. Minor word classes are usually small sets of words with a very definite membership: this, these, that, those form such a set. There is no possibility of adding more words to the list. In fact, these sets can usually be subdivided until we are left with single words that have a unique distribution; there is no other word quite like this or of. The words in the major classes are the sort of words we tend to consult a dictionary about, so they can be thought of as lexical items (lexicon means dictionary). We do not usually want to look up words like the, of or my, but only words like the following: nouns conifer, cupboard, gratitude, partisanship, path, quietness,… verbs appear, boil, consider, improve, represent, speak, synthesize,… adjectives coniferous, grateful, hot, legal, pusillanimous, quiet, wide,… adverbs beautifully, inadvertently, legally, quietly, recently, soon, well,… Words such as these are sometimes called content words, since they tend to have denotations and to constitute the main part of
the subject-matter of what we say. Thus the sentence, My criticism may surprise the performers, can be reduced to a kind of skeletal sentence: criticism surprise performers. The other words, my, may and the belong to minor classes. They are structure words; their chief function is to signal how the content words fit together and fit the context. In some cases they depend on, or are attached to the content words; e.g. my criticism, may surprise, the performers. At other times they stand in place of content words. For instance, in My criticism may surprise them, the word them stands in place of something that has already been mentioned; the
performers, perhaps.