I lived in various countries till I was 18 and I came back to my home country the same year and I'm living here up till now. I was raised in a family where my parents are both non-English speakers but me myself used English at school and with my friends. In casual talks, I'm okay with both. I am more comfortable studying and giving public speeches in English. Technically, if I go by order, English is my second language. But I started feel a discrepancy between my first language and my second language ever since I came back to my home country. I realized when it comes to academics English is my dominant language. So if I consider speaking both languages in both casual and formal settings, English would cover both while my first language would only cover the first case. But I am not quite familiar with idioms or colloquialism in English. I always identified myself as a native to my country and I am quite sure I also culturally align with my country as well. BUT I consider my language identity is English for I am more comfortable expressing and organizing thoughts. in it.

In an effort to seek an answer to this, I asked ChatGPT to evaluate my language proficiency of both languages. It said that based on the conversations we had for the past two days, it came to a conclusion that English is NOT my first language (ofc I shouldn't trust it completely). But the thing is that it made the judgement based on the fact that I spoke too formally and directly in a manner that native speakers wouldn't do in a casual conversation. But wouldn't the level of formality further prove that you are more proficient and fluent in that language? Do you think this is a valid reason to judge whether certain language is their mother tongue or not? As I mentioned in the earlier paragraph, I don't use many idiomatic expressions when I use English. But just because of that, does that make English my second language? What do you think?