Grammar is correctly spoken language. We learn it by osmosis. There is no way we can learn it analytically, anymore than a yoga student can learn yoga by reading a book about a particular asana and then suddenly be expected to move into it without some kind of neurological pathway development in the body first. I mean, we do need bodies to speak languages. It’s not a thing purely of the mind, as some would have it.
So, when being observed once, the administrator connected the stuff that I put on the board (to clarify the comprehensible input) to grammar. He saw the links between grammar and: