Reply #2: The essential problem

[SheilaT]

is that grammar is not taught in school anymore. I'm not sure they even learn anything at all about tenses, unless they take a foreign language. And foreign language teachers complain bitterly that they have to teach English grammar before they can teach the grammar of the foreign language they're trying to teach.

As an aside, someone I know honestly thought that English didn't really have tenses because your verbs don't change the way they do in the languages he'd studied (Spanish and German). He didn't understand that the way we use helper verbs IS the way English marks tenses. And this from a decently educated man who speaks correctly and writes very well, making very few errors along the way.