Vowels in the English language are classified on basis of their sound in pronunciation. A vowel in the English language can be defined as a letter in the alphabet whose sound in speech is with an open mouth without constriction of the vocal tract to cause pressure whatsoever. Commonly, these letters are: a, e, i, o, u with w and y being considered as part of them recently. The most common sound in English vowel pronunciation is referred to as the Schwa. This is however not covered in this paper.
Vowels can be viewed either as being long or short. Long vowels sound long when pronounced. One clear observation in written long vowels is that there are two vowels; a and e, separated by one consonant. For example the words ate; lake and ape are a reflection of long vowels of the vowel [a].The vowel [a] has its short version such as shown in words like sack. The vowel [e] has both its long and short versions as well. Eat and feet are words showing a long [e] sound while nest shows a short sound of [e]. Under the vowel [I], the word site and it show the vowels long and short versions respectively. The long version of the vowel [o] is as in owl, while its short version can be shown as in off. Considering the vowel [u], words such as union and but represent its long and short forms respectively.
Another classification of vowels the back and front. Back vowels sounds are from the back of the mouth. For example, words like white; cult and mount are viewed as application of back vowels. Front vowelled words on the other hand have their sound produced from the front of the mouth and considerably with a relaxed tongue. Examples of monosyllabic words in this class are net, thought and gift. Generally, back vowels are a, o and u while front vowels include the e, ö and ü sounds.
Further classification is based on the order of vowels contained in one word. Diphthongs are eminent in this class. Diphthongs are simply the result of a combining two different sounds. Putting two vowels together in a word is evidence of a diphthong. For instance, au in fault, [o-u] in drought, [o-I] in noise and [o-y] in joy among others are examples of diphthongs.
The presence of an r sound in the end of a word following a vowel changes the sound of the vowel. This leads to a classification which we can refer to as the r controlled sounds. For instance ar as in bar, er as in her, ir as in hair, or as in more and ur as in fur.
It is worth noting at this stage that as we give examples of monosyllabic words ending in letter ‘t’ on basis of different vowel forms, some words we may give do not even exist in the English dialect. For instance, words like ufo though an example of long vowel words is not in the English dialect. In addition, examples of words as we move from A to C alternate quantitatively. In letter A, the words are few while the number of words increases in letter B and tends to decrease in the case of letter C.
Based on stress in pronunciation, it can be observed clearly that those words with letter B bear more stress in sound compared to those with letter C. Words with a letter C following a vowel can therefore be considered more of lax.
There are problems in carrying out this exercise. One has to be conversant with vowel phonetics which is not easy to learn and understand. Moreover, one needs also to have a rich knowledge of English vocabulary apart from the day to day words we use in communication. Wide research needs also to be carried out if conclusions of this exercise are to be relevant.