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A vs. An: What's the Difference?

Edited by Aimie Carlson || By Harlon Moss || Updated on October 26, 2023
"A" and "an" are indefinite articles, with "a" used before consonant sounds and "an" before vowel sounds.

Key Differences

"A" and "an" are both indefinite articles in English, signifying a non-specific item or quantity. While "a" is used in front of words that begin with a consonant sound, "an" is placed before words that start with a vowel sound.
Consider pronunciation when choosing between "a" and "an." It's the sound that determines the correct article, not necessarily the letter. For instance, "a user" is correct because "user" starts with a "y" sound, a consonant. On the other hand, "an hour" is correct as "hour" begins with a silent "h" and an "ow" sound, a vowel.
Both "a" and "an" help to introduce something not previously known to the listener or reader. When mentioning something for the first time, we might say "a book" or "an apple." Once it's known, specific articles like "the" might be used.
It's essential to remember that "a" and "an" are used with singular nouns. If speaking about one non-specific cat, we'd say "a cat." For one non-specific egg, it would be "an egg."
While "a" and "an" might seem insignificant, they play a pivotal role in the structure and clarity of sentences. Misusing "a" and "an" can lead to awkward phrasing and confusion.

Comparison Chart

Sound Before

Consonant sound.
Vowel sound.


A book.
An apple.

Use with Acronyms

A UN agency (you-en sound).
An NBA team (en-bee-ay sound).

Presence in Common Phrases

A lot, a few, a little.
An ounce, an inch, an hour.

In Front of Silent "H"

A historic (when "h" is pronounced).
An hour (when "h" is silent).

A and An Definitions


"A" is an indefinite article used before consonant sounds.
She has a cat.


"An" denotes one among many or an example of something with vowel sounds.
Can I have an orange?


"A" introduces a noun not previously specified.
I saw a movie last night.


"An" is used before acronyms or abbreviations starting with vowel sounds.
She's an FBI agent.


"A" precedes singular nouns to introduce them nonspecifically.
A child needs love and care.


"An" introduces a noun not previously specified with vowel sounds.
She's an artist.


"A" is used in expressions of quantity.
She has a few friends in the city.


"An" precedes singular nouns to introduce them nonspecifically when starting with vowel sounds.
There's an umbrella in the corner.


"A" denotes one among many or an example of something.
She wants a coffee from that shop.


"An" is an indefinite article used before vowel sounds.
He ate an apple.


The first letter of the modern English alphabet.


And if; if
"an it please your majesty / To hunt the panther and the hart with me" (Shakespeare).


What are "a" and "an"?

"A" and "an" are indefinite articles in English.

When should I use "a"?

Use "a" before words with consonant sounds.

How about "an"?

Use "an" before words with vowel sounds.

Can I use "a" or "an" with plural nouns?

No, they're used with singular nouns.

Can "a" come before a vowel letter?

Yes, if the vowel has a consonant sound, like "a university."

Are "a" and "an" used with singular nouns?

Yes, they're used with singular nouns to introduce them nonspecifically.

Is it "an historic" or "a historic"?

Both are used, but "a historic" is more common in American English.

Do native speakers always get "a" and "an" right?

Most of the time, but there can be regional variations and exceptions.

Is there a historical reason for "a" and "an"?

Originally, "an" was used before all nouns. Over time, "n" was dropped before consonant sounds, leading to "a."

How do "a" and "an" affect the meaning of a sentence?

They introduce something not previously known to the listener or reader.

What if the noun starts with a silent letter?

Focus on the sound, not the letter. Use "an hour" but "a historic event."

Can I use "a" or "an" with non-count nouns?

Typically, no. We don't say "a water" or "an information."

Do "a" and "an" have specific plural forms?

No, for plural forms, the article "some" is often used.

Are there rules for "a" and "an" with adjectives?

The rule applies to the sound of the adjective, like "a red apple" but "an interesting movie."

Can "a" and "an" change the emphasis in a sentence?

Yes, especially in spoken English. "A book" might mean any book, while emphasizing "a" could mean a particular book.

Do other languages have equivalents to "a" and "an"?

Yes, many languages have their forms of indefinite articles.

Can "an" be used before a consonant letter?

Yes, if the consonant has a vowel sound, like "an hour."

Can I omit "a" or "an" in sentences?

Omitting them can change the meaning or make the sentence grammatically incorrect.

How do I use "a" and "an" with acronyms?

Focus on the sound of the acronym, like "a NASA spacecraft" but "an FBI agent."

Why is it "a European" but "an honor"?

It's based on sound. "European" starts with a "y" sound, while "honor" starts with an "o" sound.
About Author
Written by
Harlon Moss
Harlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Aimie Carlson
Aimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.

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