I've always noticed ESL students who have progressed to fluency have a significantly better understanding of English from a technical standpoint. I know most of

I've always noticed ESL students who have progressed to fluency have a significantly better understanding of English from a technical standpoint. I know most of the rules by "gut feel", but they can actually recite the rule, identify parts of speech, etc. As a result I expect they would do better than I (a native speaker) on an extremely pedantic English exam.