What are cardinal vowels? Describe and classify the English vowels.

Vowels in the English language are A, E, I, O, U, and
sometimes Y. The different ways of pronouncing vowel sounds, singly or in combinations,
allow the consonants of the English language to be connected into
words.

"Cardinal vowels" are not a different set of vowels
than those listed above. Instead, the cardinal vowel system is a way to think about how
the different parts of the mouth and tongue are placed and used in order to make the
sounds associated with different vowels. The cardinal vowel system considers the amount
of open space inside the mouth (height), the placement toward the front or back close to
the throat (backness), and the shape and placement of the lips (roundedness) when
articulating any given vowel sound. See the placement chart provided on the link below
for an illustration of the relationships between these factors.