Teaching about Language
Let's begin by separating for a moment the teaching of language in general from the teaching of grammar. Grammar is part of the study of language and should be treated as such; but for the moment it is useful to isolate much of what goes under the heading of "grammar," all of which is controversial, and treat the rest of language instruction independently. Perhaps when our general teaching goals in respect to language have been clarified, you and I will have a better idea of "what to do about grammar."
To begin, then: What does it mean to say that English teachers need to teach about language? You can start by suggesting what it does not, or should not, mean. It does not mean, for example, that English teachers should take on the role of guardians of the language. Ours is not the job of "language preservation," whatever that dubious term means. If anything, our job is more like "language analysis," but that is not quite it either, for analysis depends on terminology and classifications that may or may not be helpful to students. Instead of analysis, two other terms suggest themselves-- understanding and exploration.