Hello, I'm John Russell.
Let's explore the difference between two vowel sounds: /u/ and /u:/.(注：此音标写法为便于编辑，正确写法见视频)
In previous videos, I described the /u/ vowel sound as the sound of models, and the /u:/ vowel sound as the sound of schools.
But let's explore the difference between these sounds in a little more depth.
Let's start with the tongue.
Both sounds have a high tongue position at the back of the mouth.
But to make the /u:/ the sound, your tongue should be a little higher.
There is also an important difference in the lips.
When you make the /u/ sound, your lips should be a little more relaxed.
For the /u:/ sound your lips should be more tense. /u/ /u:/
/u/ is more of a pure vowel sound, whereas /u:/ is a vowel that is followed by a very faint semi-vowel, sometimes called an off-glide.
That is why some pronunciation books spell the /u:/ sound as /uw/.
One problem is that /u/ and /u:/ vowel sounds have some similar spelling patterns.
Both can have "oo" spellings, as in: neighborhood, school.
And both can be spelled with the letter "u", as in: push, super.
You can practice making the difference between these sounds with short words.
For example, try saying "good food". (good food)
That's all for today.
Keep up the good work.