When I ask kids to tell me what they know about vowels, I usually hear some version of "A, E, I, O, U! And sometimes Y!" Sometimes, kids will volunteer a little more, such as, "they have long and short sounds". Are they right? Absolutely! Is that the whole story? Nope, there is so much more to the vowel concept.
The letters A, E, I, O, and U are called vowel letters because they exclusively produce a vowel sound when we read them. We say "sometimes Y", because the letter Y can make a vowel sound, but it also makes a consonant sound. A vowel sound is any sound in speech that is voiced with an open mouth and no impediment of the sound from one's tongue, teeth, palate, or lips. Our mouths literally drop open when we make vowel sounds.
Try it with your children! Place your fingers beneath your chin and practice saying long and short vowel sounds in a mirror. You will notice that the mouth always drops open, more or less depending on the vowel sound. When you make a consonant sound, like /t/ or /p/, the mouth barely opens and the sound is constricted in some way. Be careful to kindly correct your children if they are adding a vowel sound to the end of a consonant sound. They should not be saying "tuh" or "puh" for /t/ and /p/, because then they are making two sounds, not one.
Ok, so now we understand that vowel sounds are voiced, unrestricted sounds that can be spelled with single letters or pairs of letters. But why is it important to teach our children about vowel sounds? The answer is that it is the most important cache of information that they will be carrying forward when they begin to read and spell multi-syllable words. Because a syllable is defined as a segment of a word that contains a single vowel sound, we can learn to break words up into syllables by identifying the vowel sounds in a word, and their corresponding spellings.
A syllable must contain a single vowel sound but include the entire vowel spelling. For example, the word "bifurcate" contains 4 vowels, but only three vowel spelling patterns, therefore we can break it into 3 syllables. We will know to divide the second syllable after the r, because the vowel spelling pattern is the r-controlled vowel "ur". The proper syllable division is bi-fur-cate. Notice the last syllable has two vowels, but the single vowel sound is spelled with the vowel-consonant-e pattern. I could go on and on about vowel sounds, but you can discover more for yourself. Challenge your kids to find out how many vowel sounds there really are in the English language! (Hint: many more than you might expect!) Happy vowel-hunting!