'Native' language ability does not extend to writing, reading comprehension, vocabulary inventories and critical thinking.

We have two NES contributors to this forum that provide ample evidence of these native language deficits.

To be sure, there are errors in writing that are specific to NES and there are many regional 'vocabularies' that are generally limited to the native population of those regions, but the vagaries of these 'local jargons' are deficits in generating precise efficient communication.

We have one NES poster on this site who hides his language deficit behind the raincoat of jargon.