• Nouns make up one of the eight word classes (or “parts of speech”) in English. (The other word classes are: determiners, pronouns, adjectives, verbs, adverbs, conjunctions, and prepositions.) Nouns are the headwords (or “heads”) of noun phrases; in other words, a noun phrase must contain one “main” noun on which all the other words in the phrase are “centered.” Moreover, because of the possibility of unitary constituency, a single noun can be, and often is, an entire noun phrase in itself.
• Traditionally, the term “noun” has been defined as “the name of a person, place, or thing.” Such semantic definitions can be useful, especially in a classroom. It should always be kept in mind, however, that they can never be completely accurate, and that it is always preferable to define grammatical concepts in grammatical terms. One indication of why this is so: when nouns are defined semantically as words which name “things,” they are typically being contrasted with ”verbs,” which are semantically defined as “action words,” but this approach seems to be in sharp conflict with the existence of nominalizations of verbs which seem to be both nouns and action words (for example, “mountain climbing” and “long-distance running”).
• Nouns are divided into two main classes proper nouns and common nouns. Proper nouns are the names of people (George), places (Shanghai), months (July), days (Wednesday), festivals (New Year’s), books (Robinson Crusoe), etcetera. Within a particular context, a proper noun has a unique reference, i.e. it can be used to refer to one and only one thing. Proper nouns usually begin with a capital letter, (but some words spelt with an initial capital are not proper names.) Proper nouns are usually not preceded by an article, but there are exceptions to this rule.
• Common nouns are subdivided into count nouns (chair) and non-count nouns (butter). Semantically speaking, the difference between the categories is that count nouns must be “seen as denoting individual countable entities” (note 1) whereas non-count nouns “must be seen as denoting an undifferentiated mass or continuum” (note 1). The words “must be seen” are important in these definitions: there are numerous non-count nouns like “furniture” which refer to things which are in fact “countable entities” (beds, tables) but which are “seen as a mass ” when referred to as “furniture.” Finally, there is another quite small but important class of nouns which belong to both count and non-count categories. Some of these nouns, “paper,” for example, show a definite change of meaning between the count and non-count versions, but in other cases, “cake,” for example, there is little change in meaning.
“ There is another distinction — between abstract and concrete nouns — which cuts across the count / non-count distinction. There are count and non-count concrete nouns (apple, milk). And there are also count and non-count abstract nouns (problem, literature). Despite the fact that this distinction cuts across the count / non-count distinction, it remains true, generally speaking, that count nouns are concrete and non-count nouns are abstract.