And that's somewhat based on the fact that we, as a society, don't respect the teaching profession enough to either pay teachers enough or hire people who are actually qualified. And it's gotten well into a domino effect now, where teachers didn't learn enough grammar (or whatever) to teach it well. Certainly primary school teachers are taught to be teachers, not necessarily to understand the subjects they are supposed to be teaching, and the fact that a majority of adults in the US seem not to even understand simple concepts like the difference between subjective and objective cases (in other words, when to use ``I'' and when to use ``me'') means that the same majority is also teaching our kids to not know the same things.

I'm not saying that everyone should know what a gerund is, but they should know that a word ending in `ing' is a verb modified to work as a noun, or at least the concept behind it. (In a comparative manner, all Perl programmers should know that $a{'index'} references an array indexed by arbitrary keys, but there's no reason that they should need to know that it's called a dictionary or hash or associative array or whatever it's called in Perl, unless they need to talk about the language itself.)