Articles are a unique type of adjectives that indicate which noun (person, place, or thing) you’re talking about. The only definite article in English is the, and it refers to a specific noun. Indefinite articles (a or an) refer to nouns more generally.
Indefinite Articles
Indefinite articles refer to non-specific nouns. Think “I need a pen” or “I want an orange.” In both cases, we aren’t referring to a specific pen or orange. The indefinite articles let you know that we’d accept any pen or orange.
The above examples also demonstrate when to use a versus an. If the word following the article begins with a consonant sound, you should use a. If it begins with a vowel sound, you should use an. So if you added the word large to describe the orange you want, the sentence would become “I want a large orange.”
Definite Articles
The definite article
Articles for Singular and Plural Nouns
A and
The works with both singular and plural nouns. If you want a specific orange or specific oranges, you could say “I want the orange,” or “I want the oranges.”
Mass Nouns
Mass nouns are any nouns that can’t be counted. This makes them neither singular nor plural. Liquids are a great example of mass nouns. You’d still use the article the for specific mass nouns, but for non-specific ones, you wouldn’t use an article at all. For example, both “The water is on the floor,” and “Water is on the floor,” are correct. The first refers to specific water, while the second doesn’t.
There’s one exception where you can use a or