The English language has six vowels: a, e, i, o, u and, in some instances, y. However, the English language has many more vowel sounds. These are generally divided into two categories: short vowel sounds and long vowel sounds. Although there are many exceptions, there are a few general rules that apply to short and long vowel sounds.
Short Vowel Pronunciation
As the name would imply, short vowels have a much shorter pronunciation than long vowel sounds. Short vowels produce only one sound and do not require the speaker to open his mouth very wide. The speaker's jaw is relaxed and barely moves during the production of short vowel sounds. The speaker's tongue is placed in different positions but is also usually relaxed. Short vowels can occur in stressed syllables, such as "o" in offer, or unstressed syllables, like the first "o" in tomato.
Long Vowel Pronunciation
Many long vowel sounds are diphthongs, which combine two short vowel sounds into one long sound. Long vowel sounds require the speaker to move the mouth from a closed position to an open one or vice-versa. The speaker's tongue glides into position during pronunciation and is often tense. When pronounced, long vowel sounds share the same pronunciation as vowels when they are pronounced as part of the alphabet.
Short Vowel Spelling
Although English spelling patterns are difficult and usually contain many exceptions, there are a few general rules that differentiate short and long vowel sounds. Words with only one vowel, especially when they are sandwiched between two consonants, often produce a short vowel sound, such as dog, tin or well. Short vowels are also usually correct when they appear in isolation at the beginning of a word, such as ant, up or end.
Long Vowel Spelling
Long vowel sounds have more complicated spelling patterns and more exceptions than short vowel sounds. Words that end with a silent e, such as bake, lone or mule, often produce longer sounds. Another common spelling pattern for long vowel sounds is two vowel sounds placed together, for example: root, oaf or through. Many long vowel sounds also occur when there is one vowel at the end of words, such as do, why or go. Many o or i sounds followed by two or more vowels, such as cold or might, also produce long vowel sounds.