badger wrote:gzt wrote:... it's one of those things native speakers know much better than learners...
don't native speakers know *everything* better than learners ?
As someone above mentioned, grammar. I lost count how many times I've had to explain to a heritage Russian speaker some point of their own language's grammar. The younger my interlocutor, the more I knew about their grammar. The older Russophone speakers were more impressed with my grammar usage (thank you, DLI Russian teachers!), and were frankly impressed that I knew grammatical terms in Russian.