I am confused with language settings. Apparently they can be made in two places, but new languages can be installed in one place. I installed Finnish language in my (mkusb) persistent live session. Tried it and later changed settings. Then at some point it showed that Finnish language is not even installed, but it was used in menus etc. even after reboot. If I re-installed Finnish language, chose it, re-logged in, and later chose English, re-logged in, I could switch to English again.