[cgio]

I will disagree. I cannot see how a native speaker can be the worst at understanding their own language. Your own language is the one you understand best, and even though that is not directly the opposite statement, for your statement to be correct it would mean that statistically native speakers are of inferior understanding compared to others. When you take that to apply for all languages you would end up with a paradox. You give an example based on pronunciation, which does change for all languages, so I would not take knowledge of history of pronunciation to have anything to do with the instinctive understanding of concepts in your mother tongue. Now on the second part, I.e. the ability to explain, I would think it’s related to understanding, but it is more nuanced as it also has to do with knowledge of the language in which the explanation is articulated.

—-edit to add comment on pronunciation of β

On the specific pronunciation subject, I am no expert in the matter but I do wonder how that reconciles with the fact that the letters μπ make the sound b in Greek and that combination of letters is not modern but has been in Ancient Greek words too, such as in εμπνέω.

[kubami]

I think what the OP means is that on average native speakers understand the language intuitively, while most of the non-natives were taught the rules and structure of the language directly. Being a non-native english speaker I experienced this often. I have never gotten a useful answer for a question about english from English people. It usually was "oh, I just feel which word is right"...

[harperlee]

I find the same. My wife is from another country and we find she has more command of my mother language’s rules and whys and viceversa.

For example she had a hard time expressing when does she say “oui” and when does she say “si”; being such a basic word (probably learnt at age 2), she never had to sit and try to infer the rule explicitly. Whereas every french-as-second-language speaker, this is a basic (explicit) rule that has been discussed in class and memorized before being internalized.

And having the rules more explicitly in the head enables hard reasoning over them, which goes beyond intuitiveness in some contexts.

[cgio]

That’s why I separated the treatment of understanding and explaining. I would still argue that a native English speaker has better skills to explain an English word in English - on average.

[YeGoblynQueenne]

>> On the specific pronunciation subject, I am no expert in the matter but I do wonder how that reconciles with the fact that the letters μπ make the sound b in Greek and that combination of letters is not modern but has been in Ancient Greek words too, such as in εμπνέω.

It's possible that "μπ" was not pronounced "b" as today, in ancient times, but as "mp". For example, I think Cypriot Greeks tend to pronounce another consontant dipthong, "ντ" as "nt" rather than "d".