How to Use "A" and "An" Correctly

Using "A" Correctly

Use "A" before all words that begin with consonant sounds. In English, nearly all words that begin with consonants will be preceded by the article "A." For example: a pet, a door, a green onion, a cat, a hysterical joke.

Understand that there are some exceptions to this rule. Some words may be spelled beginning with vowels but be pronounced with initial consonant sounds. Words that begin in h, y, u, and eu or "e" are common words that can cause confusion. Use "A" when u makes the same sound as the y in you: a union, a unicorn, a used napkin, a usability study. Use "A" when o makes the same sound as w in won: a one-legged man. Use "A" when eu or "e" makes the same sound as y: a European trip, a ewe lamb Do not use "A" when the h is silent.

Read words aloud if you're unsure. Sometimes, the way the word looks on the page is not enough to tell you which article to use. Read the word aloud in the way it sounds appropriate to you, and then base your article use on that.

Using "An" Correctly

Use "An" before all words that begin with vowel sounds. In English, nearly all words that begin with vowels will be preceded by the article "An." For example: an apple, an elbow, an Indian.

Understand that there are also some exceptions to this rule. Some words may be spelled beginning with consonants but be pronounced with initial vowel sounds. Words that begin in h are the most common causes of confusion, but there are some other letters that can pose a challenge, too. Use "An" before a silent h: an hour, an honorable peace, an honest error. Use "An" before words that are spelled with consonants but pronounced with vowel sounds: an MBA.

Understand that pronunciation may vary depending on geographical location. For example, British and American pronunciation of certain words varies dramatically, particularly words beginning in h such as "herb." In American pronunciation, the h is silent, so correct usage would be "an herb." But in British pronunciation, the h is pronounced, so correct usage would be a herb.

Understand that the word "historic" is a special case. There is substantial debate over whether the correct usage is "a historic event" or "an historic event." Nearly all style handbooks and usage guides prefer "a historic event," citing the consonant sound explanation given in this article. However, you may see "an historic" crop up from time to time, particularly amongst British writers. Some American writers will also use "an" with longish words (three or more syllables) beginning with H, where the first syllable isn't accented: "a hypothesis," "an habitual offender."