Anybody who shifts gears when he writes for children is likely to wind up stripping his gears. But I don’t want to evade your question. There is a difference between writing for children and for adults. I am lucky, though, as I seldom seem to have my audience in mind when I am at work. It is as though they didn’t exist.
Anyone who writes down to children is simply wasting his time. You have to write up, not down. Children are demanding. They are the most attentive, curious, eager, observant, sensitive, quick, and generally congenial readers on earth. They accept, almost without question, anything you present them with, as long as it is presented honestly, fearlessly, and clearly. I handed them, against the advice of experts, a mouse-boy, and they accepted it without a quiver. In Charlotte’s Web, I gave them a literate spider, and they took that.
Some writers for children deliberately avoid using words they think a child doesn’t know. This emasculates the prose and, I suspect, bores the reader. Children are game for anything. I throw them hard words, and they backhand them over the net. They love words that give them a hard time, provided they are in a context that absorbs their attention. I’m lucky again: my own vocabulary is small, compared to most writers, and I tend to use the short words. So it’s no problem for me to write for children. We have a lot in common.