The 'eh' as in 'bed' vowel sound. To make this sound, the jaw drops, eh, and the tongue remains forward with the tip touching lightly behind the bottom front teeth. Eh. The mid/front part of the tongue raises somewhat towards the roof of the mouth while the back of the tongue feels like it stretches wide, eh, eh, bed.
Here is the 'eh' as in 'bed' vowel on the right, with the mouth at rest on the left. And here we see the parts of the mouth drawn in. The soft palate, as with all vowels, is raised. It is the mid/front part of the tongue that is somewhat raised. But the tip of the tongue still rests against the back of the front bottom teeth. Sample words: feather, spend, benefit. Sample sentence: French bread is best when it is very fresh. 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.
French, the bottom lip moves up to the ff position, and then the mouth opens into the 'eh' as in 'bed' vowel. See that jaw drop. Tongue moves up to make the N, ch. Bread, again, the 'eh' as in 'bed' vowel. And again the tongue moves up to make the D. Is best. Another 'eh' as in 'bed' vowel. When. Now here you will see that the tongue is not down, and that the jaw does not drop as much. This is because the word when is not stressed in this sentence. It is shortened. It is still the 'eh' as in 'bed' vowel, but because it is so quick, the mouth does not form the true position, and the tongue is moving up into position for the N in 'when'. It is very - with the 'eh'. Here the tongue position appears to be slightly different. And that is because the tongue is beginning to move into position for the R consonant sound in 'very', even as the jaw has dropped for the 'eh' as in 'bed' vowel. So the tongue does not stay down in the eh position long. This is typical of the R consonant. It tends to take over the vowel that comes before it in the same syllable. Fresh, 'eh' as in 'bed'. And here is the same sentence from an angle.
French, the bottom lip moves up to make the F and the jaw drops for the 'eh' as in 'bed', but the tongue quickly moves up to make that N. Ch. Bread, again, the jaw drops for the 'eh' as in 'bed'. And again the tongue moves up to make the D in bread. Is best, lips come together for the B, and the jaw drops, be-, best. When, with the shorter eh vowel, and you can see the tongue moving up into position for the N. It is. Bottom lip comes up for the V, very, and here is the eh, but the tongue is not completely forward, as it is already moving back for the R sound. Very. Bottom lip moves up to make the F in fresh. This is a good shot of the 'eh' vowel. You can see the tip of the tongue is lightly touching behind the bottom front teeth, and the tongue is raised a bit in the front/mid to make this eh vowel sound. That's it, and thanks so much for using Rachel's English.