Both function words and content words follow and proscribe specific sets of orthographic patterns. I teach all about these – and how to study them with kids – in my Function & Content Continuum LEXinar.
Some people think this means that just identifying whether a word is a function word or a content word explains everythingin this regard, but it doesn't. It's richer and more complex than that.
For example, let's take the words here, there and where, and the word some. I'm sure I've written about these before, somewhere, but the nonsense is swirling in the Facebook groups again, and it's like Pavlov's bell for me.
To hear the Facebook folks, these are function words and that's why they are spelled as they are, but that makes NO SENSE, because a replaceable <e> always marks a lexical (content) spelling. So what gives? Which is it?
Here is some straight orthographic talk for folks who seek an understanding not just of words, but of words in their families, in order to understand the system.
No nonsense, go guesses, no feel-good echo chamber. There you go.