Confused about vowel diagram (Vowel chart)! Can you clarify & explain how to read it?

Question

Ok, here is the English vowel chart:

I'm really confused, what do "front" "central", "back", "close(high)", "close-mid", "open-mid", "open (low)" mean?

Ok, Here is what I understood, please correct me if I am wrong.

Ok, let's look at the vowel /i/ which is in the position of "front" & "close (high)". In this position, the tip of the tongue still touches the bottom teeth, but the front of the tongue will be placed high and touch the very front roof of the mouth. The lips are very spread out when saying /i/. See the picture:

Now, look at the /ɪ/ which is in the position of between "font" & "central". It is also in "close-mid" position. In this position, the tip of the tongue still touches the bottom teeth, but the front of the tongue is placed high and in the position between the front & the central roof of the mouth. However, the front of the tongue does not touch the roof of the mouth. The lips are still spread out but less so than with /i/. See the pic below:

Ok, now, consider the /u/ which is in the position of "back" & "close (high)". In this position, the tip of the tongue still touches the bottom teeth, but the back of the tongue is raised very high and touches the very far back of the roof of the mouth. The lips are very rounded in this position. See the pic below:

Ok, now, look at the /ʊ/ which is in the position somehow between "central" & "back". It is also in the position "close-mid". In this position, the tip of the tongue still touches the bottom teeth, but the back of the tongue is raised high and somehow between the middle and the back of the roof of the mouth. The lips are rounded in this case but less rounded than /u/. See the picture below:

Ok, now take a look at the /ə/ which is in the "central" position. It is also in between "close-mid" & "open-mid". In this position, the tip of the tongue still touches the bottom teeth, but the middle of the tongue is raised right to the middle of the mouth. Of course, the tongue does not touch the middle of the roof of the mouth. The lips are neutral in this position. See picture below:

Ok, consider /æ/ which is in the middle of "open-mid" & "open (low)". It also stays between "front" and "central". Technically, if the distance between "front" & "central" is 10, then /æ/ will stay in the distance of 7 which means it will have 7 units to the "front" and 3 units to the "central".

In this position, the tip of the tongue still touches the bottom teeth, but the whole tongue is low but not really low like /a/. The front of the tongue somehow stays in the position between the front and the middle of the roof of the mouth, but the front of the tongue is closer to the middle of the roof of the mouth than to the front of the roof of the mouth. The lips are spread out in this case. See the picture below :

Am I wrong about anything?

Could you clarify and explain how to read the vowel diagram?

Answer 1

The Original Poster's descriptions are correct in terms of words, but the actual position of the tongue is a bit more complicated. The diagrams here are not correct. This is because the official terminology is very misleading.

Unfortunately, the named parts of the tongue do not correspond to intuition or common sense. When you look in the mirror your tongue looks kind of flat and thin. This is an illusion. Your tongue is really a big fat ball with a bit stuck on the front of it.

When we talk about the tongue, there is the front bit which we use for consonants. We can flap it about in all kinds of different ways. That's the blade of your tongue. It doesn't count for vowels in any way. The part of the tongue that we use for making vowels is the big ball of muscle behind that. It starts where the your tongue joins the floor or your mouth.

In the stylised diagram above, the blade of your tongue is represented by the small pink rectangular section. The square behind that represents the ball of your tongue. Now when we talk about "front" vowels and the "front" of your tongue raising, we are talking about the front of this back part of your tongue. So when you think of your tongue in normal everyday terms, this is actually about half way down your tongue as you look at it in the mirror. This is what raises towards the roof of your mouth when you make an [i] vowel. The blade of your tongue does nothing at all.

So the horizontal axis of the vowel quadrilateral shows whether it is the front of that bulky part of the tongue or the back of it that "is raising up". The vertical axis represents the distance between the tongue and the roof of the mouth.

Answer 2

You don't have the correspondence between front vowels and the consonants right. The front vowels correspond to the palatal consonants (not the labial and dental consonants, which are anterior, not front).

The Sound Pattern of English classification is a standard, though probably most phonologists have some disagreements with it. The correspondence between the vowels and place of articulation is drawn with the tongue-body features, high/back/low (and maybe coronal): palatal consonants and front vowels are +high, -back, -low; velar consonants and [u] are +high, +back, -low; uvular consonants and /o/ are -high, +back, -low; pharyngealized consonants and [a] are -high, +back, +low.

The chart you are using was probably constructed from measurements of the first and second vowel formants, rather than by measuring tongue positions, and those formants are associated with cavities in the mouth more than with place of articulation. The front vowels have high second formants because the cavity in front of the main tongue constriction is small. So it may help in thinking about classification to think in terms of the size of resonant cavities.