Close this search box.

What Makes a Vowel a Vowel?

Can you name the English vowels? If you rolled your eyes and answered A, E, I, O, U and sometimes Y, you’re on the right track, but you’re still missing nine out of fourteen correct answers, including epsilon, open o, ash, and the schwa. But let me back up for a minute. Before we can talk about quantifying vowels, we need to discuss what exactly a vowel is and what it is not.

Rule number 1: A vowel is not a letter – it is a sound

This is the most crucial rule for breaking away from that list of five letters and a sixth ‘sometimes’ letter that most of us have used to conceptualize the vowels throughout our lifetimes. While it’s true that those letters are often used to represent vowels, the vowels are the sounds that correspond to those letters, not the other way around. And in English, most of the time, that correspondence is rather messy.

Think about the ‘a’ at the beginning of the word ‘apple,’ and the ‘a’ at the end of the word ‘sugar.’ Are they the same sound? No. The ‘a’ at the end of the word sugar sounds more like the ‘e’ sound in ‘banker,’ or ‘water.’ Here, we have two different sounds being represented by just one letter. Now compare these ‘a’ sounds to the ‘a’ in the word ‘prawn.’ That’s another sound, again being represented by the same letter.

If you try this experiment with the other vowel letters, you begin to realize that all of them can represent many different sounds, and often there is no system to the sounds that one letter does or doesn’t represent. For example, think of the words ‘true,’ ‘few, ‘sioux,’ and ‘two.’ All of them contain the same vowel sound, and yet that sound is represented by a different letter or combination of letters in each word. In fact, that vowel sound, which corresponds to a lowercase u in the international phonetic alphabet, can be represented in English using fourteen different combinations of vowel letters.

How did this happen? Why doesn’t English use the sensible one letter one sound approach of Spanish or Finnish? For starters, we simply don’t have enough letters to represent all the different sounds we use. Since the ninth century, English has used the Roman alphabet, which was originally used for Latin. In Latin, each vowel did represent just one sound. There were the short vowels – a, e, i, o, u – and the long vowels, which were pronounced the same but were longer in duration – ā, ē, ī, ō, ū. However, as Old English speakers were conquered, first by the Vikings and other Scandinavian groups who spoke Old Norse, then by the Normans, who spoke Norman French, the English language began to incorporate a wide array of new vowel sounds that could not all be accounted for by just five letters. This begs the question: what exactly makes a vowel a vowel? How did we decide which of the new sounds were vowels and which were consonants?

Rule number 2: Vowels are vocalized

Vocalization is one of two defining characteristics of all vowels, and it just means that the vocal cords are vibrating whenever a vowel is produced. If you place your hand on your throat and make an ‘ah’ or ‘eeee’ sound, you should be able to feel the vibrations. If you do the same but make an ‘s’ sound, which is a non-vocalized consonant, you shouldn’t feel anything. However, as you may have guessed by the term ‘non-vocalized consonant’ there is also such thing as a ‘voiced consonant,’ such as ‘v’ or ‘z,’ which means that we need another rule to finish carving out the vowels from the consonants.

Rule number 3: Vowels are produced with an unobstructed vocal tract

This concept is perhaps easier to understand if we look at the defining characteristic of all consonants: an obstructed vocal tract.

There are two main categories of consonants: stops (also known as plosives) and fricatives. Stops, including P, B, T, D, K, and G are all produced by creating an obstruction along the vocal tract, either by closing the lips (P and B), bringing the tongue to the alveolar ridge (T and D) or lowering the velum at the back of the mouth (K and G). Air pressure is then built up behind these obstructions and suddenly released to produce the stop-plosive sound.

With fricatives, such as S, F, V, and Z, a narrow constriction is created in the mouth, and air is sent through it in a steady stream. With the letter S, the constriction is between the upper and lower teeth. With F, it’s between the upper teeth and the lower lip, and so on and so forth. This majority of consonants are produced in one of these two ways.

In contrast, vowels are produced without any obstructions. You might change the position of your lips, rounding them to make an ‘oo’ sound or pulling them apart to make an ‘ee’ sound, but the air is flowing out of the mouth freely, without any impedance by the teeth, tongue, or other articulators.

Now that we have a better understanding of what exactly a vowel is and isn’t, we can start to think of the vowel sounds as existing on a spectrum. Try moving from a prolonged ‘ee’ sound into an ‘ahh’ sound into an ‘oo’ sound without stopping. When you do this, you may begin to notice that all of these sounds occur along a continuum, and there are a lot of ‘in-between’ sounds from one vowel to another.

Native English speakers distinguish between fourteen different sounds along the vowel continuum. The rest are what we would consider those ‘in-between’ sounds. Because of the complex history of English, this number is a lot higher than the majority of languages, which tend to recognize only five or six vowel sounds. Therefore it’s easy for an English speaker to hear the difference between words like ‘cheap’ and ‘chip,’ or ‘sheep’ and ‘ship,’ while a Spanish speaker – equipped with just five vowel sounds – may find it nearly impossible.

Why ‘And Sometimes Y’?

If you’ve gotten this far, you may have started to wonder what’s going on with the letter Y. Why can’t we make up our minds about Y, and what does it even mean to be a ‘sometimes’ vowel? This gets a little bit confusing, because the ‘and sometimes Y’ adage is rooted in the – hopefully now discarded – idea that vowels are letters rather than speech sounds. The ‘and sometimes y’ notion speaks to the fact that, in written English, ‘y’ is sometimes used to represent a consonant sound (a sound characterized by a restriction or obstruction), but it is also sometimes used to represent a vowel sound (unobstructed, with vibrating vocal cords). In the word ‘yes,’ for example, Y is being used to represent a consonant sound. In the word ‘gym,’ it’s being used to represent a vowel sound.

If we’re going off written language, though, there are actually a lot more ‘sometimes’ vowels and even some ‘sometimes’ consonants. In the word ‘wet,’ W is a consonant, but in ‘now,’ it’s part of a diphthong vowel. H is a consonant in ‘hard,’ but in ‘ah’ or ‘uh’ it’s representing a vowel (compare ‘ah’ with ‘a’). Similarly, you might consider the sounds that the O represents in the word ‘one,’ or the U represent in ‘united.’ ‘Wuh’ and ‘yu’ respectively, are both consonants, not vowels.

For most of us, A, E, I, O, U, and sometimes Y is enough to suffice. After all, most of the time, these are the letters used to represent the vowel sounds, and Y does tend to vacillate more than the others.

But it’s worth keeping in mind that vowels and consonants are not letters on a page – they are the sounds of speech that the letters on the page are charged with representing, and most of the time that charge is fulfilled quite imperfectly and sometimes, even chaotically.

Learn more about ALTA’s language services, including translation, interpreter training, interpretation, and testing.

Janet Barrow writes about the places where language meets history, culture, and politics. She studied Written Arts at Bard College, and her fiction has appeared in Easy Street and Adelaide Magazine. After two years in Lima, Peru, she recently moved to Chicago.

Other Resources

November is Native American Heritage Month

Native American Heritage Month has officially been celebrated in the United States each November since 1990. This is recognized on the federal, state, and local levels with special programming and events to highlight and honor the traditions, culture, history, and...

Learn More

5 Fascinating Facts About the Hawaiian Language: A Look into its History and Significance

Hawaiian language, also known as ʻŌlelo Hawaiʻi, is one of the two official languages of Hawaii. While the language was banned in schools after the overthrow of the Hawaiian Kingdom in 1896, there have been revitalization efforts since 1978. Today...

Learn More

What is Heritage Language?

Individuals who speak multiple languages or live in multilingual households may have a “heritage language.” This term describes the language the individual speaks or hears at home, but it is not the dominant language spoken in the community. In the...

Learn More

Contact Us

Get Started Today

Interested in our language services? Complete the form or call us during business hours (9 AM to 6:00 PM ET) at 800.895.8210.

Preparing for your test?

View our test prep materials or FAQ’s for common questions about taking a test.