What is a diphthong and how to teach diphthongs


How to teach your child to say the long A sound.  If your child is struggling to produce the long A sound as in RAIN…..please read below.  There are strategies listed below to help you help your little one. 

Before the strategies you will find information about diphthongs…how many diphthongs are in the English language…and exactly what a diphthong is.  I hope that you find this post helpful.  I will be sure to post about the 7 other diphthongs when I can.


A diphthong (pronounced difthong) is a vowel that actually consists of two vowels in a single syllable, in which the sound begins as one vowel and moves toward another (as in coin, loud, and side).  Diphthongs are considered single phonemes, each having a sequence of two different vowel positions.  One of the positions is the dominant nucleus (sometimes called the radical) with greater duration; the other position, the glide (or vanish), is of reduced duration and stress.  Both positions are taken in a single syllable.  All diphthong phonemes of American-English move from the nucleus to the glide position. 

The children I have been working with all seem to have difficulty with the glide part of the diphthong.  My experience has been that they are capable of producing the nucleus….however delete the glide completely.  When given a verbal and visual cue…and when just producing the diphthong in isolation….they are capable of producing both the nucleus and the glide.  However….once in a word….the glide is deleted. 

To improve your little one’s ability….it is best to start off with words that are consonant-vowel words (and do NOT have a consonant that follows the vowel).  An example of this would be the following…..best to start off with words like: BYE……..and work towards words like: BIKE.  Both of these words start off with the consonant B…..followed by the same diphthong…however, in the word: BIKE…..the consonant K ends the word….making it a little more challenging. 




There are eight English diphthongs altogether. To make diphthongs, your tongue, lips and your jaw at times……have to move. Sometimes the movement your tongue makes is short and very controlled; in some of the diphthongs, it has to move a long distance in your mouth, involving a lot of jaw movement too.

Diphthongs are difficult because producing them is a motor skill (like increasing the strength of the muscles in your body).  Therefore, practice is important if you want improved results.   Your little one will be able to make improvement through awareness of the following: the manner of articulation (e.g. the absence or presence of lip rounding &/or tension and degree of jaw movement), the starting and finishing tongue positions, and both the direction and extent of tongue movement.


 How to teach your little one to say the Long A sound:


         as in day, pay, say, lay.

The velopharyngeal port is closed and the sides and the back of the tongue are closed against the upper molars.  The middle and front of the tongue is raised toward the palate and alveolar ridge.  The tongue than briefly rises….then the tip of the tongue touches lightly behind the lower front teeth.  The first part of the diphthong is the longer nucleus and the second part of the diphthong is the shorter glide. 


This sound is the long A sound in English.  The long A is made of up two sounds….the short E sound as in BED…..and the long E sound as in BEE.  When you put these two sounds together you get the long A sound.  You can practice making the short E sound and then follow it by the long E sound. 

When you make the long A sound….the first part of the diphthong is called the nucleus…and the first part of the diphthong/nucleus in the long A  is the short E sound…and then you follow the nucleus with the glide….the long E sound.  A little confusing I know…please reply with any questions.

When I work on the long A diphthong….first I have the child practice the short E sound in isolation/by itself.  And remember the short E is the sound in BED.  So have your little one say: 

e-e-e-e-e-e  (remember this is the short E sound)

Next I would have the child make the long E sound…

E…….stretching out the E sound during production.  Use the visual cue that follows to help your little one “see” that the long E sound continues.

Visual/Physical Cue:

One of the ABA teachers I work with called this the “taffy” cue……so imagine that you are holding a piece of taffy between your hands….held together by your pointer fingers and thumbs…..then you are going to pull the taffy apart…..stretching your fingers/hands apart…..the picture above is the best one I could find to give you the visual cue…..remember to start at midline(the middle of your body) with both hands together….only pointer and thumbs touching…..then as you stretch your fingers out….make the E sound…..you should stretch to the length of your shoulders…

Once your little one is able to produce the short E and the long E….she may be ready to try in simple words:


C-V words:
















In my experience I have found that the little ones that struggle with the production of diphthongs most frequently have difficulty with the glide portion of the diphthong.  This is the second part of the diphthong.  So when we practice…..I start of with words that are C-V words. As you can see above.  What does this mean?……look above at the word list.  All of the words start off with a consonant (C) and end with a vowel (V).  The words do not end with a consonant.  This makes the word easier to say with regard to oral motor skills and abilities. 

After your child has mastered the above word list….the next step is to add a consonant to the end of the word…so follow the list below:


 C-V-C words:
















Now when I work with the two little ones that I see for “diphthong therapy”…..this is the order of “diphthong therapy”


1.Nucleus sound..short E sound only

2. Glide sound….long E sound only

3. Syllables…..short E followed by long E

4. C-V words: use list above

5. C-V words in phrases, then short sentences, longer sentences, conversation

6. C-V-C words:  use list above

7. C-V-C words in phrases, then short sentences, longer sentences, conversation


Have fun with your little one or big one!


About Kim

My name is Kim Marino and I have been practicing as a licensed speech and language pathologist since 1993. I work on Long Island providing diagnostic evaluations and services to children from birth to age 21. My experience is vast and am proud to say that I work with children that may present with articulation and phonological concerns, oral motor feeding concerns, Down Syndrome feeding, cognitive rehabilitation, auditory processing delays, receptive language delays, cleft palate feeding and sound development and expressive language delays. Most importantly, I am the mother of four amazing children and am happily married to my childhood sweetheart. I feel blessed to have my four children and so lucky to share this journey in life with my husband. I always had it somewhere in my head that I wanted to develop a blog or a website of some sort so that I could provide families with an additional resource....so that parents could help their little ones become a better communicator. And as I was developing this blog....I realized that I also needed to share the stories about my life and my children....and the funny things along the way that help to keep me smiling. Whether you are a working mother or not...finding balance between home, children and life can be a challenge....I hope that my blog helps to bring a smile to your face..and also some tools to help you help your little or big one. I hope you enjoy! Kim
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