Today’s Wonder of the Day was inspired by Olivia from West Helena, AR. Olivia Wonders, “What makes a vowel a vowel and a consonant a consonant?” Thanks for WONDERing with us, Olivia!

A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, and Z! Now you've read your ABCs…and we bet you also sang them to the tune of the familiar song we all learn growing up. Didn't you? Admit it!

Did you know that the letters of the alphabet can be divided into two different categories? It's true! What are we talking about? Vowels and consonants, of course!

The 26 letters of the alphabet can be sorted into two groups: 21 consonants and 5 vowels. However, as you'll learn in just a bit, at least one letter — y — can fall into either group depending upon its context.

The 5 vowels are A, E, I, O, and U. The 21 consonants are…well…all the other letters. How did the vowels come to be called vowels and all the other letters consonants? It's all about how you say them.

Vowels are pronounced with an open mouth and no trapped sounds. Give it a try. Say A, E, I, O, and U. Did you notice how your lips don't have to close to make these sounds? Airflow remains constant as you pronounce vowels.

The word “vowel" comes from the Latin word vocalis, which means “speaking." The word “consonant," on the other hand, comes from the Latin word symphonon, which means “pronounced with." This is appropriate, since consonants are pronounced with trapped sounds.

In other words, you have to block the flow of air in some way with your mouth, lips, or tongue when pronouncing consonants. Try it out. Say B, C, D, F, and G. Did you notice how each of these letters requires you to block the airflow in some way? For example, saying the letter B requires you to block airflow with your lips. The letter D requires you to block airflow with your tongue by pressing it to the roof of your mouth.

If you've learned about vowels and consonants in the past, you've probably heard that the vowels are A, E, I, O, U, and sometimes Y. That's because Y can be a vowel or a consonant depending upon how it's used.

The Y in “sky" would be a vowel, because it sounds like the vowel I. The Y in “yoga," however, would be a consonant, because it is pronounced in a way that requires a blockage of airflow. Think of several other words containing the letter Y. Which ones use Y as a vowel and which ones use Y as a consonant?

One other helpful way to differentiate between vowels and consonants is to realize that vowels can be spoken alone, while consonants cannot. Say A, E, I, O, and U. When you say those vowels, you're saying the vowel and that's it.

Now say B, C, D, F, and G. If you think about it, you're probably really saying “bee," “see," “dee," “ef," and "gee." So when you say the consonants, you can't really say them without the help of the vowels!

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