There's the kind of grammar that lives inside your brain, and if you're a native  speaker of a language or a good speaker of a language, it's the unconscious rules that you follow when you speak that language.
Postoji gramatika koja živi u  vašoj glavi i ako ste izvorni govornik ili dobar govornik jezika to su nesvjesna pravila koja slijedite  kada govorite taj jezik.