Deleted english language : can't get it back and bug

Moi EtOuir

New member

I deleted the english language (I don't even remember why, but I did). Now I'd like to get it back because it would help me understand some styling properties etc.

How can I get it back ? There is no English file on the language forum

Another thing : When I try to modify my admin account preferences (index.php?account/preferences), I get this error :
"Please select a valid language"