Soft feathers, The shining sun are not sentences, and for similar reasons. Feathers are soft, The sun shines are sentences. Here the asserting word is supplied, and something is said of something else.
The shines sun is not a sentence; for, though it contains the asserting word shines, the arrangement is such that no assertion is made, and no thought is expressed.
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LESSON 3.
A TALK ON SOUNDS AND LETTERS.
We have already told you that in expressing our ideas and thoughts we use two kinds of words, spoken words and written words.
We learned the spoken words first. Mankind spoke long before they wrote. Not until people wished to communicate with those at a distance, or had thought out something worth handing down to aftertimes, did they need to write.
But speaking was easy. The air, the lungs, and the organs of the throat and mouth were at hand. The first cry was a suggestion. Sounds and noises were heard on every side, provoking imitation, and the need of speech for the purposes of communication was imperative.
Spoken words are made up of sounds. There are over forty sounds in the English language. The different combinations of these give us all the words of our spoken tongue. That you may clearly understand these sounds, we will tell you something about the human voice.
In talking, the air driven out from your lungs beats against two flat muscles, stretched, like bands, across the top of the windpipe, and causes them to vibrate up and down. This vibration makes sound. Take a thread, put one end between your teeth, hold the other with thumb and finger, draw it tight and strike it, and you will understand how voice is made. The shorter the string, or the tighter it is drawn, the faster will it vibrate, and the higher will be the pitch of the sound. The more violent the blow, the farther will the string vibrate, and the louder will be the sound. Just so with these vocal bands or cords. The varying force with which the breath strikes them and their different tensions and lengths at different times, explain the different degrees of loudness and the varying pitch of the voice.