An article is a word that is used before a noun. It is always used to give some information about a noun. There are three articles in English: a, an, the. Articles can be classified as either definite or indefinite.
Definite article (The)
Refers to a specific, particular object
I sat on the couch at my grandma’s.
I found the paper that Jon had been looking for!
Indefinite articles (A or An)
Refers to a general, rather than specific noun and indicates the noun is singular
“An” is used when the noun begins with a vowel or vowel sound (a, e, i, o, u)
I have a migraine.
I need to buy a book.
I need an owl.
I have an hour until work starts. (hour begins with an h, but it makes an “our” sound)
Vowel sounds (h)- history vs. hour
History makes a “hiss” sound, whereas, hour makes an “oww” sound. Since the “oww” has a vowel sound, you need “an” instead of “a”.
***Articles in English have no gender, number, or case specifics. A, An, and The are used regardless of gender, number, and case.***