Most students of language learn quickly what a "noun" is. One common definition is that a noun is "a word used to denote a thing, a person, a place or an abstract idea."
book (thing)
accountant (person)
classroom (place)
knowledge (abstraction)
Similarly, most students of language also learn that, when one wants to add information about a noun, one can use an "adjective" (interesting) or a noun functioning as an adjective (company).
interesting book
company accountant
English classroom
perfect knowledge
Adjectives (or modifying nouns) are, however, not the only kind of words used to add information about a noun. English, like many other languages, also makes use of a system of "articles." This system has four components. These are: a, an, the, and something called "null article," which in grammar books is usually written as Ø.
a book
an accountant
the classroom
Ø knowledge
The article an has the same meaning and use pattern as a; it is used in place of a when the following word begins with a vowel sound:
an accountant
an everyday task
an NTID student (the N of NTID begins with the sound "eh")
Articles allow a writer to communicate more clearly basic information about each noun. For example, each of the following pairs of examples below has a slightly different meaning.
a book
the book
Ø books
the books
Types of Nouns
In order to understand the article system in English, one has to first know something about English nouns. Nouns can be divided into different categories. The two most important categories for the purposes of this module are:
1. Count versus Non-Count (or Mass) Nouns
2. Singular versus Plural Nouns
Two additional factors crucially affecting article use will also be explained:
3. Specific versus General Nouns
4. Known versus Unknown Nouns