This document discusses the use of articles (a, an, the) in English. It explains that articles are adjectives that modify nouns. The definite article "the" refers to specific nouns, while the indefinite article "a/an" refers to non-specific nouns. It provides examples of when to use definite vs. indefinite articles and discusses rules about using "a" vs. "an" depending on the sound of the following word. The document also covers uses of articles with count/non-count nouns and in geographical contexts.