It is more difficult to make a long sentence clear than it is to make a short one clear. If, then, you are a poor writer and want to make sure that youngsters understand you, stick to short sentences. Unfortunately, a long series of short sentences, like a long stretch of writing with no “hard” words, is irritating to anyone intelligent, young or old. A youngster is particularly offended because he thinks (sometimes with justice) that the writer thinks that because the youngster is young, he is therefore stupid. The book is at once discarded. (This is called “writing down,” by the way, something I try never to do.)
The trick is to write clearly. If you write clearly enough, a long sentence will hold no terrors. If you hit the proper mix of long and short, and hard and easy, and make everything clear, then, believe me, the youngster will have no trouble. Of course, he has to be an intelligent youngster, but there are a larger percentage of those than of intelligent oldsters, for life hasn’t had a chance yet to dull the youngsters’ wits.