What is "international day of mother tongue" called in your mother tongue?
My mother tongue is Polish, so it's "międzynarodowy dzień języka ojczystego".
I didn't even know that was a thing. Well, my native language is English so you already know I guess. lol
I didn't either. It appears to be a UN thing.
It has an intesting history. "The date commemorates a rare battle fought in the world history for one’s mother tongue."
Lá Idirnáisiúnta na Máthairtheangacha, is the official translation, but it strikes me as a literal translation largely for the sake of this particular phrase (even though it uses the plural Máthairtheangacha/"languages") - the normal phrase used in Irish to refer to a persons "mother/native tongue/language" is teanga dhúchais, where dúchas can be understood as "heritage" or "traditional", or something that has been passed down to you.
The Unesco International Mother language day is translated to "Journée internationale de la langue maternelle" (French) . Here is a Wikipedia link: https://en.wikipedia.org/wiki/International_Mother_Language_Day And here is the Unesco link who created this day in 1999: http://www.unesco.org/new/en/unesco/events/prizes-and-celebrations/celebrations/international-days/international-mother-language-day-2017/