How common are noun-case errors among people who have a high school education? I mean something like using the elative case when the ablative might be more appropriate?
Nonexistent. I don't think even preschool children ever mix those. I don't have kids, so I can't say how it is with the kids who are just learning to speak.
Also in English, you don't see people mixing "into" and "onto" even remotely as often as the mistakes the linked article talked about.
Nonexistent. I don't think even preschool children ever mix those. I don't have kids, so I can't say how it is with the kids who are just learning to speak.
Also in English, you don't see people mixing "into" and "onto" even remotely as often as the mistakes the linked article talked about.