I think your example is instructive. That's not really an "error", so much as a rule people learn in school about how English "should" be spoken and may or may not pass along to their children. But consider this conversation:

child: "My brother said me -"

adult: "My brother told me"

child: "{pause} My brother told me..."

That conversation just doesn't happen. Those are the real grammatical rules of English, and the ones that native speakers of Spanish, in this example, violate. But a child doesn't learn that from an adult interrupting them and correcting them, they just internalize it and know it on their own.