I thought that my choice of the word "commonly" indicated that I was not talking about the limits of the possible.
You really think it's common for L2 speakers to achieve native-like levels of proficiency? Where do you live and who are these geniuses? I'm serious. For example, I see people speaking at conferences who have lived in the US for years, but aren't native speakers, and they are still not doing so with native-like fluency and eloquence. And presumably you have to be more than averagely intelligent to give a talk at a scientific conference...
I'm not talking about just any kind of fluency here, and neither was fubarobfusco, I assume. I suspect I was trying to i...
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.