rdearman wrote:My grandfather lived in the USA his entire life. He only spoke English for 70+ years. He read the instructions on how to program a VCR to record his favorite TV shows, he read it and reread it again and again, and people explained it to him a number of times, but he could never manage to program the VCR and his grandchildren had to do it for him.
Therefore, using your logic, my grandfather WAS NOT A NATIVE SPEAKER, and he wasn't even CLOSE TO NATIVE!
The person describe someone who struggled to get their car repaired... the proof they're not C2 is that they struggled with anything, not that they lacked specific knowledge or skills.
There's a simple test for this - I'm a so called native speaker of the American language. Sports are very popular in my country and actually a huge part of small talk. I am almost completely incapable of talking about sports; I know nothing. But I have the following ability:
I can effortlessly remember details in a conversation about sports because I can readily identify "ok - that thing he just mentioned must be a type of maneuver allowed in the game" "ok - that thing he just mentioned must be a role for a player in the game" etc. in spite of the fact that I have never heard these things before.
Moreover, this requires so little effort (relative to let's say a B2 speaker trying to remember anything complex with new words and manipulate it in real time) that I can actually hold a fluid conversation in spite of my complete ignorance. On top of that, the other person will feel I'm listening and actively engaged enough that they won't mind telling me everything they find interesting about the sport they're going on about.
Likewise, if I didn't know "how to get my car repaired" the missing vocabulary would be completely irrelevant, as the mechanic would realize that I could use circumlocutions with such expertise that the conversation about how we were going to get the car fixed would scarcely take longer than if I was fully aware of all the necessary specialist vocabulary.
Someone who was a true C2 would approximate these abilities VERY closely, and that's a world of difference away from "not being able to "get the car repaired". Someone who couldn't is not a C2 plain and simple. Your grandfather would have all of the above.