The language of the site changes automatically depending on what language do you learn and from what language. I don't know if you understand my words or not, but for example : I'm learning English, French from Arabic. and Japanese,Esperanto from English. so, when I study English or French the site will change automatically the native language to Arabic.while if I study Japanese or Esperanto the site will change it to English.

So all you have to do is change the language you're learning