The AY diphthong
The AY vowel is a diphthong vowel. Diphthong vowels are made of two sounds, so that means each diphthong has a starting position and an ending position, and you should feel your articulators move as you say the sound.
Something unique can happen to vowels when they are part of a diphthong. They don’t sound as pure as they do when they are said by themselves. The AY diphthong is made up of these two vowels, /e/ and /ɪ/. But the final sound of AY doesn’t sound like a pure IH like in bit vowel. The jaw is a little more closed and the tongue is a little higher in the final sound of AY than when the IH vowel is said by itself.
AY. IH. AY. IH.
You don’t need to focus any of your time on why the IH vowel sounds different in a diphthong. As long as your mouth position is correct as you progress through the diphthong, then you’ll be making the correct sound.
Stressed vs. unstressed AY
Watch my mouth position as I say the word day. At the beginning of the vowel, the mouth is open. The tongue is forward, and the tongue tip is low, behind the bottom front teeth. Then as I progress through the vowel, the jaw closes, and the tongue arches up closer to the roof of the mouth. The tongue tip stays behind the bottom front teeth.
When AY is in a stressed syllable, the pitch of my voice glides up and then down. AY. Day.
But in an unstressed syllable, the AY vowel is pronounced at a lower pitch with a flatter shape and it’s said for a shorter duration. AY. AY.
Close-up of stressed AY and unstressed AY
Here is a close up of what AY looks like in an unstressed syllable, like in the word always.
The stressed AY diphthong is in the top pictures, and the unstressed AY diphthong is in the bottom pictures. Notice the difference in the jaw opening between the stressed and the unstressed positions. When AY is in an unstressed syllable, the jaw is more closed than in the stressed syllable. The ending mouth position of the stressed and unstressed syllables is similar.
It is common to simplify or reduce the pronunciation of diphthongs when they are in an unstressed syllable. Native speakers simplify the pronunciation so that the unstressed syllable can be said quicker than the stressed syllables.
Stressed AY. Day. Unstressed AY. Always.
Practice words and sentences
Here are some practice words and sentences:
Tray. AY. Tray.
Place the tray in the upright position.
Birthday. AY. Birthday.
Today is my birthday.
Payment. AY. Payment.
Your payment is past due.
Away. AY. Away.
The bird flew away.
Freeway. AY. Freeway.
Don’t speed on the freeway.
Monday. AY. Monday.
Monday is a holiday.
Thanks so much for watching! And let me know how I can help you with pronunciation of the American English diphthong vowels!