With your question of how someone's native language can change, it's nothing to do with it- it's a question of only being able to choose a single option from a list, while many people are bilingual or more. Having to choose one may not be so straightforward.
Please try to keep things on an even keel. Fighting impoverishes forums.
I can cut a long story short because everything is published and can be reread. I still cannot see what was so impolite about what I wrote, it was even meant to be funny and humorous: Many a true word is spoken is jest. And what about the two first replies in the current thread then? Besides, there are people who are quick in dealing blows to others, but are oversensitive themselves when it comes to the taking. As to the changed profile: The trigger for changing it is obvious. I asked a simple factual question because there happen to be interferences between different languages. It could have easily been that from a point of view of a non-English native speaker the present perfect could have been understood as a preterite. But the responses were nothing but mere mock, not just in the overtone, but bluntly. Everybody can read it.
Thanks for your commitment.
Wszystkiego najlepszego!
My sentiments exactly! Be assured that there is no risk of any fighting going out from my part.
Just for your attention: I was not going to write any more contributions in the now closed thread anyway. I see, however, that you had to act responsibly when a thread becomes a threat in the very sense of the word.
By the way, you tried to send me a personal message, but I failed to open it. Could you have another try?
I agree with you that the thread had become unpleasant before your post on freezeframe's profile. It sometimes happens. I think it's important to cut these things off before they have to be cut off by moderators.
Wszystkiego dobrego również Tobie.
Just en passant, talking of fighting, it is always a potential source of conflict to call a spade a spade. What if from an academic point of view a claim is absolutely wrong as e.g. the asserted existence of a certain language (I do not want to give it a name), and that very person feels attacked without any reason? Who is to blame?