The primary diphthongs in English

What is a diphthong?

A diphthong is a single-syllable sound that involves a glide or movement from one vowel sound to another within the same syllable. The term “diphthong” comes from Greek, meaning “two sounds” (di- “two” + phthongos “sound”). Unlike pure vowels, which maintain a consistent sound (like the “a” in “cat”), diphthongs shift from one vowel position to another, creating a smooth transition.

Characteristics of diphthongs

• They are pronounced as one continuous sound, not two separate vowels. A diphthong is a single vowel sound that’s actually made up of two distinct vowel sounds blended together. It’s like the vowel sound “glides” from one position to another. Both vowel sounds happen within the same syllable. This is what makes them different from just two vowels next to each other.
• The tongue and/or lips move during the articulation, starting with one vowel sound and ending with another. The key is that the transition between the two vowel sounds is smooth and seamless.
• They are typically found in stressed syllables.

How to identify diphthongs

Sometimes the spelling of a word doesn’t clearly show that it has a diphthong and they can be tricky to spot. To spot a diphthong, try saying a word slowly. If your mouth changes position mid-vowel within a single syllable, it’s likely a diphthong. For instance, in “ride,” your tongue starts low and moves upward—compare that to “red,” where the vowel stays steady.

Diphthongs are a key part of what makes English pronunciation dynamic and varied! Let me know if you’d like examples specific to an accent or more detail.

Notes on pronunciation

• In some accents, additional diphthongs may appear, or certain diphthongs might be pronounced as pure vowels (monophthongs). For example, in some British accents, “poor” might have a diphthong /ʊə/, while in American English, it’s often a single vowel.
• The symbols above (e.g., /aɪ/, /eɪ/) are from the International Phonetic Alphabet (IPA), used to represent sounds precisely.

The most common

English has about 8 main diphthongs, though some linguists might have slightly different classifications. Here are some of the most common ones:  

• /eɪ/ (as in “day”): This starts like the “e” in “bed” and glides to the “i” in “bit.” Think of words like “day,” “say,” “play,” “face,” “late.”
• /aɪ/ (as in “my”): This starts like the “a” in “father” and glides to the “i” in “bit.” Think of words like “my,” “time,” “like,” “high,” “cry.”
• /ɔɪ/ (as in “boy”): This starts like the “aw” in “saw” and glides to the “i” in “bit.” Think of words like “boy,” “toy,” “coin,” “oil,” “voice.”  
• /aʊ/ (as in “now”): This starts like the “a” in “father” and glides to the “oo” in “food.” Think of words like “now,” “how,” “cow,” “out,” “loud.”
• /oʊ/ (as in “go”): This starts like the “o” in “hot” and glides to the “oo” in “food.” Think of words like “go,” “no,” “slow,” “home,” “bone.”
• /ɪə/ (as in “near”): This starts like the “i” in “bit” and glides to the “er” in “her.” Think of words like “near,” “fear,” “beer,” “ear,” “here.”
• /eə/ (as in “hair”): This starts like the “e” in “bed” and glides to the “er” in “her.” Think of words like “hair,” “fair,” “care,” “there,” “wear.”
• /ʊə/ (as in “tour”): This starts like the “oo” in “book” and glides to the “er” in “her.” Think of words like “tour,” “poor,” “sure,” “lure.”

Tips for learning diphthongs:

• Listen carefully: Pay close attention to how native speakers pronounce words with diphthongs.
• Practice slowly: Try saying the words slowly and consciously feel your mouth moving between the two vowel sounds.
• Record yourself: Record yourself speaking and compare it to a native speaker’s pronunciation.
• Use resources: Look for online videos or audio recordings that focus on diphthong pronunciation.

Keep learning:

• R-controlled vowels
• Silent E words

Advertisement