Indefinite Articles: A vs. An Grammar Rules

A and An Grammar Rules – A lot of people learned the rule that you should put a before a word that starts with a consonant and an before a word that starts with a vowel. However, it’s actually more complicated and not that simple. Let’s take “hour” as an example, “an hour” sounds better but “a hour” reads more correct since “h” is a consonant.

a and an grammar rules

A and an grammar rules

To answer which one is correct, we’re going to do more in-depth discussion about a and an grammar rules below. But before answering the question, let’s learn about a and an as indefinite article first.


What Is Indefinite Article?

Indefinite article is used when the other person doesn’t know which person or thing exactly you’re talking about. It also can be used when you’re referring to an unspecified person or thing. Indefinite articles can modify only a singular noun.

    I met a beautiful girl yesterday at the town park. (We don’t know about the girl specifically.)
    There was a huge hole in the road. (I haven’t mentioned about this hole before.)
    I want to be a dedicated and thoughtful teacher. (A dedicated and thoughtful teacher in general.)
    Could you bring me a pair of scissors? (Any pair of scissors will be okay.)

A vs. An Grammar Rules

There are two indefinite articles in English: a and an. The indefinite article a should be used before a noun begins with a consonant sound and an should be used before a noun begins with a vocal sound.

1. Use a when the indefinite article comes before a word beginning with a consonant sound.

    a book
    a horse
    a table

2. Use an when the indefinite article comes before a word beginning with a vowel sound (a, e, i, o, and u).

    an apple
    an end
    an earphone
    an oak
    an uncle

Useful Hints for A and An Grammar Rules

Many beginners in English make mistakes in determining a or an because they only pay attention to the first letter of a word instead of the sound. It’s important to note that not all words that begin with a consonant letter also begin with a consonant sound, and vice versa. So, the point here is about the sound; how we pronounce the first letter, not the letter itself.

Be particularly careful when choosing an indefinite article because some words beginning with a consonant letter make a vowel sound. Consider the following examples:

    a Honorary Fellowship (incorrect)
    an Honorary Fellowship (correct)

    a hour (incorrect)
    an hour (correct)

    a X-ray machine (incorrect)
    an X-ray machine (correct)

Similarly, there are some words beginning with a consonant letter that makes a vowel sound. You should take care with words that begin with “yew” sound. They should be precede by a even if the “yew” sound is formed by a vowel letter. Look at the following examples:

    an university (incorrect)
    a university (correct)

    an European (incorrect)
    a European (correct)

    an Utopian society (incorrect)
    a Utopian society (correct)

    an one-way street (incorrect)
    a one-way street (correct)


Using A vs. An with Acronyms

The same rules above are also can be applied to acronyms; a is used for an abbreviation with consonant sound on its first letter and an is used for an abbreviation with vowel sound on its first letter.

    We need a MC for the event. (incorrect)
    We need an MC for the event. (correct)
    We need a Master of Ceremonies for the event. (correct)

    What can you do with a MBA degree? (incorrect)
    What can you do with an MBA degree? (correct)
    What can you do with a Master of Business Administration degree? (correct)

    A SSN is issued to permanent and temporarily U.S. citizens. (incorrect)
    An SSN is issued to permanent and temporarily U.S. citizens. (correct)
    A Social Security Number is issued to permanent and temporarily U.S. citizens. (correct)

The first and second examples above show that MC and MBA are pronounced “em” for their first letter M. In the third example, the S in SSN is pronounced “es”. So, in these cases, an is should be used.


Well, that’s all our discussion about a and an grammar rules that may aid you to understand these both indefinite articles. If you want to learn more about English, you can visit our other discussions on the given category or just check out ContohText’s index page for more English lessons about grammars, vocabularies, and text genres.


Reference:
“A, an.” Microsoft Student 2009. DVD. Redmond, WA, USA: Microsoft Corporation, 2008.
In text: (“A, an”)