How to change administrator language to English

Hi, I need your help! I recently changed my administrator account to German because someone else wanted to view our backend and they did not speak English. My account was originally created by someone else for me in English. Now, it does not give me the ability to change it back to German. The only language option displayed in the dropdown menu under my User account settings is Deutsch. I have also tried to create a new account, but it does not let me create one in a language other than German. Please help me! I want backend to be displayed in English, as this is the language I am more comforable working in. Thank you for your help! ~lvonloewen