It's a secret that isn't often told, even among writing trainers and teachers. One writing teacher who has confronted this dirty secret is Stephen Krashen, of the University of Southern California. And only one, he says, can be taught. If a learner has the first ability, we trainers can teach the second. But if a learner lacks the first ability, training cannot make him or her a better writer.
Competence is our deep, unconscious knowledge of language.
We acquire competence in a spoken language by hearing it, over and over again. We learn how a language sounds. Nevertheless, you know the rule perfectly. The English language has tens or hundreds of thousands of such practices, only a few of which ever get taught formally, in classrooms and training rooms. But many others apply only in written English.