In English there are three articles: a, an, and the. Articles are used before nouns or noun equivalents and are a type of adjective. The definite article (the) is used before a noun to indicate that the identity of the noun is known to the reader. The indefinite article (a, an) is used before a noun that is general or when its identity is not known. There are certain situations in which a noun takes no article.
As a guide, the following definitions and table summarize the basic use of articles. Continue reading for a more detailed explanation of the rules and for examples of how and when to apply them.