In John David Ward’s answer to the following Quora question https://www.quora.com/Who-are-some-well-known-linguists-and-what-are-their-noteworthy-contributions
the following statement about his nomination Otto Jespersen appears:
Jespersen was, despite being Danish himself, an expert in the grammar and history of the English language.
I bet that most people would read this sentence without any reaction. Imagine, you read something like this:
Bell was, despite being a human herself, an expert on fruit flies.
Most people would find such a sentence very strange, wondering what the point here is. Or they would interpret it as a stupid joke because obviously being of a different species has nothing to do with whether you can be an expert on it.
This comes about because of the deeply ingrained notion that language cannot be the subject of scientific inquiry. Language is culture, you just gotta, like, feel it you know. The thought that you can study a language while not even being able to speak it is completely beyond people while at the same time they would never assert that it’s strange you can study bee behaviour while not being a bee oneself.
But language is an observable cognitive human behaviour which can of course be scientifically studied. Some even dare to say that it is a window into the human mind (hey, Steven Pinker).
But before this deteriorates into a macro rant (which at some point will inevitably happen anyway) I’ll leave it at that.
PS: I’m more concerned with the ‘grammar’ part than the history one. It might be the case that by being educated in, say, UK you pick up a bit about the history of the language, in any way more than a French person would. This is pretty irrelevant for me. The point is that a native speaker of English doesn’t necessarily have any more conscious knowledge of the grammar than a non-native one.