Languages

By rules, English should be the only language used yet I see people speak Spanish, French, and such and they say it’s allowed.

I’m not against other languages being spoken but I find it unfair that only certain ones can be. When I try to use any character of the Cyrillic alphabet, it gets blocked when I attempt to send a chat with it. It should be unblocked as why can only certain languages be spoken when by rules, when it’s meant to be one? If other languages are to be allowed then why only ones that use the same alphabet as English? Please allow other characters.