Knowing which article to use in front of words can be difficult for anybody learning the English language. Knowing when to use the articles “a” or “an” can be particularly challenging. For instance, is it “a hour” or “an hour”?
“An hour” is correct since the h is silent. You should place “a” before words beginning with a consonant sound, and place “an” in front of words starting with a vowel sound. “A” and “an” are both indefinite articles we place only before singular nouns.
This guide will highlight the general rule behind “a” and “an,” run through the most common exceptions, and provide clear examples to demonstrate them. Make sure to keep reading to gain clarity once and for all regarding this unit of time.
“A” versus “An”
Even if you can instantly spot the subtle difference, let us start with the similarities between “a” and “an.” Firstly, they both are known as indefinite articles because they do not specify which person or thing we are talking about (source).
Articles go before nouns, like in these examples:
- A puppy means any puppy.
- An orange means any orange.
As you can see, we use the indefinite article to refer to a single example of puppies or oranges without specifying any particular puppy or orange.
The only other article within the English language is “the,” which is known as a definite article because we use it to refer to a specific person or thing. In other words, what were are referring to is definite or certain (source).
Compare these two examples:
- Ayla dreams of the puppy — Which puppy? It could be your family puppy.
- Ayla dreams of a puppy — Which puppy? It could be any puppy.
In the first example, Ayla dreams of “the puppy,” having a particular puppy in mind. It could be the family puppy, or it could be the neighbor’s puppy. In the second example, Ayla dreams of “a puppy,” without having a particular puppy in mind.
Secondly, it is valuable to point out that both “a” and “an” are used with singular nouns only, never for plural nouns.
The Oxford Advanced Learner’s Dictionary defines a noun as a word that refers to a person, a place, or a thing — a quality or an activity (source). Plural nouns are nouns indicating there is more than one.
Compare the following examples:
- Correct: She ate some apples
- Incorrect: She ate a apples
The same applies to uncountable nouns. The Oxford Advanced Learner’s Dictionary defines a noun that is uncountable as one that cannot be made plural or used with “a” or “an;” for example, water, bread, and information.
Compare these sentences:
- Correct: Could I have bread for lunch?
- Incorrect: Could I have a bread for lunch?
Thirdly, the differences between “a” and “an” will help you understand when to use which one in front of words, abbreviations, acronyms, or letters.
As a general rule, we use “a” for words beginning with a consonant, while “an” is used for words starting with a vowel.
If you are ready to learn about plural and possessive nouns, check out our helpful article, “Families or Family’s: When to Use Possessive Form.”
Be sure to keep resources like The Oxford English Dictionary and Dryer’s English close by — they will help you discover more definitions and meanings. You can easily find both on Amazon.
To better understand the differences between using “a” and “an” for words beginning with a consonant or vowel, here are some simple examples:
| “A” + Consonant | “An” + Vowel |
|---|---|
| A car | An ambulance |
| A girl | An eagle |
| A fruit | An orange |
| A house | An umbrella |
But what about the word “hour” since it begins with a consonant but sounds like it begins with a vowel?
The Secret Revealed! Sound Over Spelling
Here is the secret to determining whether to use “a” or “an” before words like “hour.” Ask yourself whether the noun begins with a vowel or consonant sound to determine if you should precede it with “a” or “an.”
Spelling is not the final determining factor as much as the sound. We use “a” before words with a consonant sound and “an” before words that start with a vowel sound (source).
In the English language, many words begin with a vowel and vowel sound, while others begin with a consonant but have a vowel sound (source).
| “A” with a vowel but a consonant sound | “An” with a consonant but a vowel sound |
|---|---|
| A eulogy | An honor |
| A unit | An heirloom |
| A utensil | An X-ray |
| A use | An Hour |
In the left column, we used “a” before a syllable beginning in its written form with a vowel and pronounced with a consonant sound. In the right column are singular nouns that start with a consonant but produce a vowel sound, so the article is “an.”
In the next section, you will gain insight into the exceptions and clarify why certain words, like “hour,” seem to deviate from the general rule.
Your Take-Away Tip: Make sure to say the word out loud. If it sounds as if the word starts with a consonant sound, use “a.” If you hear a vowel sound, use “an.”
- Singular noun pronounced “h” = “a“
- Singular noun with silent “h” = “an”
The Silent “H”
The silent “h” scenario is often grounds for confusion. It is important to note that English is not always a strictly phonetic language, which simply means that what we write and how we pronounce what we write can sometimes be two different things.
When a non-native English speaker has to choose the correct article to go before words like “hour” with a silent “h,” it can catch them off guard.
You do not pronounce the “h,” but there is no general rule when an “h” is silent, so I have listed the most common examples (source).
| A | An |
|---|---|
| A human | An hour |
| A humid | An honor |
| A habit | An honest |
| A horse | An heir; An heiress; An heirloom |
American English vs. British English Exceptions
There is a significant difference between the application of “a” and “and” between American English and British English when it comes to words that start with “h.” The most common ones are “historic,” “history,” “herb,” and “hotel.”
Let’s use the word “historic” as a good example to examine a little closer. You might have come across both versions, either in a book or reading material online.
- “a historic event” → most common in the United States
- “an historic event” → visible in older literature and used by British English speakers
Interestingly enough, the usage of the articles for the word “herb” is reversed.
- “a herb” → most common among British English speakers
- “an herb” → most common in the United States
Again, much of this boils down to pronunciation in the United States. The “h” is not silent in “historic,” but it is in “herb.” However, in British English, they pronounce the “h” in both “historic” and “herb.”
What About “An Hour and A Half”?
If there is confusion about using “a” or “an” before “hour,” then shear panic can hit when a non-native English speaker has to figure out “an hour and a half.”
Relying on the sounds of “hour,” which has a silent “h,” and “half,” where we pronounce the “h,” we can easily resolve the issue.
But which is correct: “an hour and a half” or “one and a half hours”? It depends on how you use it. Whether verbal or written, “an hour and a half” is the equivalent of “one and a half hours.”
The amount of time is the same, but the two structures are different.
“An hour and a half” has two singular nouns. “One and a half hours” gives a number that is more than one, namely one and a half, and therefore requires the plural noun “hours.”
- Question: “How long is the drive? Answer: One and a half hours.”
- The hour-and-a-half-long drive seemed to go by fast.”
In the first instance, “hours” is plural because we are talking about more than one hour. The numerical forms would be 1 1/2 hours or 1.5 hours. In the second example, “hour” is singular.
In short, you can use all of the variations below; just make sure that when you pick one, you apply the correct rules.
- One and a half hours → more than one, therefore, the plural noun.
- One hour and a half → hour is singular.
- One hour and a half → hour is singular.
Final Thoughts
Apart from the existence of silent letters, such as “h,” factors including mother or native tongue and educational background influence and contribute to the challenges of acquiring and developing new language skills.
For American English, the most important thing to remember is that “a” goes before words that begin with the consonant sound, while “an” goes before words that begin with a vowel sound. Still, in both British and American English, it will always be “an hour.”