The [ei] diphthong. I find this diphthong hard to classify. I've seen
some sources that use an open e sound at the beginning， that would be
the [e] as in bed ， and others that use a closed e ， which doesn't exist
on its own as a vowel sound in English. {[e]， 'ey'} And then the final
sound is [i]， the open vowel ， as in sit. Although I find it， in practice，
to be halfway between the ih as in sit and the ee as in she. The first
sound ： ey. Now in the sound my tongue ， in the very back ， is actually
touching the top of my mouth. Is it the top of my mouth ， is it the throat，
it's hard to tell because it's so far back there. Ey， ey. It's kind of
where the top of the mouth meets the throat. Where the back of the tongue
comes up to touch there. Ey ， ey. Now that's different on the eh as in
bed where the tongue is not acutally touching the roof of the mouth. Eh
，as in bed， the tongue feels a little more forward. I would say this
is eh ， ey ， ey. So it comes back a little so it can touch back there.
Ey， ey ， ey ， as you can see ， the jaw is quite closed， ey ， ey ，
and the rest of the tongue comes forward. Ey， ey. Now to go to the ih
sound ， the jaw closes even more ， ei ei ei ， and the part of the tongue
that touches the roof of the mouth is this part. So in the ey ， it's
back here that it touches ， and in the ih， it's this part that touches.
It just comes up and touches the roof of the mouth further forward.

    [ei]是一個雙元音，有些人認為它的第一個音是bed 中的[e] 音，另外一些
人認為第一個音應該念作'ey'. 此外，他們認為最后一個音是sit 中的開元音[i]
，但是我覺得應該是介于[i]和she 中的[i：] 音之間。

    念第一個'ey'音時，舌頭要放在很靠后，舌根要碰到口腔與喉嚨的連接處。

    而發bed 中的[e] 音時，舌頭是不碰到上顎的，舌頭的位置更靠前，所以說
有所區別。發'ey'時口型收得較緊，舌頭的其他部分向前平伸。接下來就要變成
[i] 音了，口型將收得更緊，之前是舌根觸及上顎，現在要將舌頭輕輕抬起，變
成舌頭前部觸及上顎。

    Sample words：

    say 說

    grey灰色

    may 可能

    Sample sentence ：

    I stayed at the bay and played all day. 我在海灣玩了一整天。