I want to explain the difference between the English linguistic terms "fluent" and "native speaker". I could do this in English, but I'd also like to know if it's possible to do so in Japanese. To be fair, I think it's not just native speakers of Japanese who blur the lines between the two. (Related posts: The Workplace, and English Language & Usage 1 2)
Is there a pair of terms in Japanese that correspond to the difference between the two English terms, which are likely to be understood by the average English learner or teacher?
In case context matters, I'm talking about English, rather than other languages.
Post where I asked for how to express "native speaker" by itself in Japanese: Difference between 母語話者 and ネイティブスピーカー