The 'ew' as in 'few' diphthong. The first sound of this diphthong is the Y consonant. Diphthongs are normally made up of two vowel sounds, but in this diphthong, the Y consonant is acting as a vowel. To make this sound, the front part of the tongue will push behind the bottom front teeth, yy, yy, while the mid/front part of the tongue will raise and actually make contact with the roof of the mouth. YY, yy, yyuu. Also, there's a sort of pinching off here in the throat that gives the Y sound that quality. Yyuu, yyuu. The second half of the diphthong is the 'oo' as in 'boo' vowel, yyuu. You may find that the lips start to form that tight circle of the vowel oo, even as you're making the Y consonant sound, yyuu, yyuu. In the 'oo' as in 'boo' vowel, the back part of the tongue stretches up towards the back of the roof of the mouth and soft palate area. So the tongue goes from being raised in the front, touching the front part of the roof of the mouth, to pulling up and stretching towards the back of the roof of the mouth. The tip of the tongue still remains forward in the 'oo' as in 'boo' vowel, jjuu, here behind the bottom front teeth, or slightly lower, in the soft tissue. Yyuu, few. Here you can see both sounds of the 'ew' as in 'few' diphthong. You can see that though in the first sound the lips are rounded, in the second sound they are much more rounded and closed.
Here are both sounds in profile. Again, note that the circle of the lips in the second sound is tighter. Here parts of the mouth are drawn in. You can see that in the first sound, the Y consonant sound, the tongue stretches up and forward. Here I have not drawn the tongue pressing all the way to the roof of the mouth because the center part of the tongue is actually leaving room for the air to pass through. So the sides of the top of the tongue are pressing the sides of the roof of the mouth, leaving a small passageway down the center. In the second sound the tongue stretches up and back. Ew. So the tongue has to make this movement from being forward and raised to being back and raised in this diphthong. Sample words: view, use, music. Sample sentence: You are one of few pupils writing beautiful poetry. Now you will see this sentence up close and in slow motion, both straight on and from an angle, so you can really study how the mouth moves when making this sound.
You, you can see the lips round, but they come in tighter towards the end of the diphthong. And the tongue moves back as you can see the space between the teeth getting darker. Are, tongue moves into the R consonant position. One, lips come small, tongue goes up to make the N. Of, the lip to the teeth to make the V sound. Few, another 'ew' as in 'few' diphthong: lips start bigger and then come in to the tighter circle. Lips together for the P, pupils, another 'ew' as in 'few' diphthong. Writing, lips form a tight R position, and then open into the 'ai' as in 'buy' diphthong. And the tongue moves up into the T position. Beautiful, another 'ew' as in 'few' diphthong here. Tongue tip up to make the T and the lip up to make the F. Poetry, the 'oh' as in 'no' diphthong. The T, then the lips make the R position, and the lips pull back into the 'ee' as in 'she'.
And now from an angle. You, the lips form and you see the tongue begin to pull back as the lips tighten into a tighter circle. Are, you see the tongue back there making the R consonant sound. One. Tongue up to make the N. Of, lip up to make the V sound, few, the lips up to make the F, and another 'ew' as in 'few' diphthong, you see the tongue moving back. Pupils, another 'ew' as in 'few' diphthong. And again the lips tighten into a tight circle as the lips move back. Writing, the tongue up to touch the roof of the mouth for the T, beautiful, another 'ew' as in 'few' diphthong. The tongue up to touch the roof of the mouth for the T. Poetry, 'oh' as in 'no' diphthong. There's the R consonant sound. And then the corners of the lips pull back into the 'ee' as in 'she' sound. That's it, and thanks so much for using Rachel's English.