How do you use the Articles of Speech a an and the in English grammar?

In English grammar, articles are used to define nouns as specific or unspecific. "The" is a definite article used to refer to a specific noun that is known to the listener, while "a" and "an" are indefinite articles used for non-specific nouns; "a" is used before consonant sounds, and "an" is used before vowel sounds. For example, you would say “a cat” when referring to any cat, but “the cat” when talking about a specific cat already mentioned.