You may have misread the concept.
SE is still supporting language sites. Each of these sites traditionally accept Q/A written either in English or in the corresponding language. For example, at Ukrainian Language.SE you can post in English or Ukrainian.
The site interface, however, (buttons, banners, menus, popups, etc.) is in English.
On the contrary, SE is holding the creation of sites having the entire User Interface (UI) in another language. Check Stack Overflow in Spanish or Stack Overflow in Japanese to see the difference.
Yet another example. There are two sites about the Russian language: with English UI and with Russian UI, and the quality of posts between the two sites differ drastically. Translation of the UI has never been completed, too:
SE still supports the creation of language sites of the former kind, but withholds the latter.
So, nothing prevents you from advocating for the creation of Turkish Language.SE.
This site, Linguistics.SE, is not actually for asking language-specific grammar or usage questions.
If your question is about the very process of language acquisition — e.g., methodology of teaching and (self-)learning a foreign language — you may ask it at Language Learning.SE.