What is a Diphthong? (Definition, Examples, Word List)

What is a diphthong? How does a diphthong work? And how do I identify a diphthong in the English language? These are all great questions that you probably have. Diphthongs are known as gliding vowels, they have a unique purpose and definition in American English. To learn all about the diphthong, continue reading this comprehensive English guide.

What is a Diphthong?

Diphthongs are also known as gliding vowels. They are sounds that have two different vowels in the same syllable. That means you move your tongue and mouth position to produce two different sounds in a sequence when you pronounce a diphthong.

Diphthongs can be syllables that exist naturally and are heard as single vowels by the listeners. But they are also formed when two vowels merge due to rapid speech in conversation.

Definition

The word “Diphthong” is derived from the Ancient Greek word “Diphthongos,” meaning two sounds. It is a vowel where the sound changes clearly from one vowel sound to another within the same syllable.

Diphthongs	Sound	Placement
“ai” “ay”	Long “a”	Middle of a word At the end
“ee” “ey”	Long “e”	Middle of a word At the end
“oa” “oe”	“Oh sound”	Middle of a word At the end
“oy” “oi”	Same sound	Middle of a word At the end

How Does a Diphthong Work?

When we pronounce vowels, we usually hold our mouth and tongue in fixed positions. These are monophthongs, where a single vowel sound is produced while we let out one burst of air in a syllable. But diphthongs are produced differently from this general case. While pronouncing diphthongs, we move our tongue and parts of our mouth from one target position to another.

This means the sound gradually shifts from one vowel to a different one within the same syllable. But this is only noticeable under close inspection. We hear diphthongs as a single vowel like any other when we are not trying to look for them actively.

Diphthongs in Phonetic Alphabets

The phonetic alphabet is a system of notation used to signify the different sounds made while speaking in a language. In the International Phonetic Alphabet, single characters (usually Latin letters) represent a monophthong.

To represent diphthongs, two vowel symbols are used to identify the two sounds that occur together to form the diphthong.

Example

The pronunciation of the word “fun” is represented as “fʌn,” where the sound for the letter “u” is given by the symbol “ʌ.” This is a monophthong.

The word “loud” is represented as “laʊd,” where the vowel sound is represented as the combination of two symbols, “aʊ.” This is a diphthong.

Types of Diphthongs

There are several types of diphthongs based on how we classify them. Let us look at these types in detail, as they will help you understand what diphthongs are more clearly.

Change of Prominence of Vowels

The first way to classify diphthongs is to consider how the prominence of the vowel rises or falls while pronouncing the diphthongs.

If the pitch and volume of the vowel decrease while we pronounce the diphthong we call it a falling diphthong (for example- “eye”). 

If the pitch and volume of the vowel rise when we pronounce the diphthong we call it a rising diphthong (for example- “new”).  

Changing of Openness of Vowels

The vowels which we produce with a more open mouth are louder. We call them open vowels.

If the diphthong has a more open vowel at the end we call it an opening diphthong (for example- “new”).

If the diphthong has a more open vowel at the start we call it a closing diphthong (for example- “eye”).

If the vowels are closer in openness and the vowel moves from a more peripheral to a central position of the mouth, we call it a centering diphthong (for example- “ear”).

Distance Between Vowel Sounds

If we alter the mouth position significantly to reach from the first vowel sound to the next in a diphthong, we call it a wide diphthong (example- “found”).

If the mouth position does not change and we form the diphthong by gliding between two adjacent vowel sounds, then we call it a narrow diphthong (for example- “rain”).

Understanding The 8 Diphthong Sounds

There are eight distinct diphthong sounds in English. Each of them has its own representation in International Phonetic Alphabets.

Let’s look at them, along with some examples, and see what letters appear in words with these diphthongs.

The phonetic symbol for the first diphthong is “ɑι.” It is usually used in words with the letters “i,” “igh” or “y.”

Examples

• My
• Cry
• Light
• Like
• Crime
• Light
• Byte

The phonetic symbol for the second diphthong is “eι.” It is usually used in words with the letters “ea,” “ey,” “ay,” “ai,” and “a.”

Examples

• Steak
• Pain
• Weight
• Break
• Prey
• Pray
• Braid
• Ache

The phonetic symbol for the third diphthong is “əʊ.” It is usually used in words with the letters “ow”, “oa” and “ough.”

Examples

• Tow
• Loan
• Tough
• Boat
• Slow
• Moan
• Dough

The phonetic symbol for the fourth diphthong is “ɑʊ”. It is usually used in words with the letters “ow” and “ou.”

Examples

• Town
• Found
• Cow
• Hound
• Crown
• Sound
• Mound

The phonetic symbol for the fifth diphthong is “eə.” It is usually used in words with the letters “ai” and “ea”

Examples

• Fair
• Hair
• Chair
• Lair
• Bear
• Air
• Stair

The phonetic symbol for the sixth diphthong is “ιə.” It is usually used in words with the letters “ee,” “ie” and “ea.”

Examples

• Leer
• Tier
• Jeer
• Pier
• Near
• Fear
• Seer

The phonetic symbol for the seventh diphthong is “ɔι.” It is usually used in words with the letters “oy” and “oi.”

Examples

• Oil
• Coy
• Foil
• Boy
• Soy
• Soil
• Boil
• Toil

The phonetic symbol for the eighth diphthong is “ʊə.” It is usually used in words with the letter “u.”

Examples

• Pure
• Lure
• Sure
• Cure
• Mule

Are Diphthongs Long Vowels?

Although diphthongs include two vowel sounds, they are not distinct vowels, we pronounce each vowel with a single exhalation.

When we pronounce two vowel sounds within a single syllable, the mouth parts and tongue have to move to accomplish it. It takes more time to do this than to keep the tongue and mouth position fixed while pronouncing a syllable.

This means, by definition, diphthongs are longer than most monophthongs. In other words, we can say that diphthongs are long vowels.

Why Are Diphthongs Important?

The diversity of the words we use impacts how well and distinctly we can express ourselves. To have a diverse group of words at our disposal we must be able to make many distinct sounds.

The more vowels we can produce, the more sounds we can pronounce. If we can combine monophthong vowels into diphthong vowels while we speak, it increases the richness of our stock of sounds. We can use the same vowels we can already produce to make new vowels which makes our language richer.

How to Identify a Diphthong

A diphthong is a vowel made by gliding from vowel sound to vowel sound. So by listening carefully, we can hear the two vowel sounds within the same syllable if it is a diphthong.

A way to identify diphthongs while pronouncing them is to notice if your tongue and mouth parts move during the production of the syllable. If it does move, then the vowel is a diphthong.

Examples of Diphthongs

Here is a list of some of the many words with diphthong vowels:

• Ache
• Air
• Bear
• Boat
• Boil
• Boy
• Braid
• Break
• Byte
• Chair
• Cow
• Coy
• Crime
• Crown
• Cry
• Cure
• Dough
• Fair
• Fear
• Foil
• Found
• Hair
• Hound
• Jeer
• Lair
• Leer
• Light
• Light
• Like
• Loan
• Lure
• Moan
• Mound
• Mule
• My
• Near
• Oil
• Pain
• Pier
• Pray
• Prey
• Pure
• Seer
• Slow
• Soil
• Sound
• Soy
• Stair
• Steak
• Sure
• Tier
• Toil
• Tough
• Tow
• Town
• Weight

Diphthong words list (images)