Translate the frontend part of the site only I am working at a project that needs a biilingual translation (content + interface). I've installed the following modules:

Locale + Content translation (core modules)
Internationalization Module (i18n)
Variable Module (required by Internationalization) – it deals with meta tags
Admin Menu


I can't find a way to:

To provide interface translation for front-end only. Admin should be in English 

Note: I assume this can be done by deactivating the language block on admin side) but how can this be done without duplicating the theme (the same theme for admin but with the block language disable).

How can this tasks could be accomplished?
The Administration Language module can do this:


  This module lets the administrator see all administration pages in her preferred language.
  
  You can use this to display the frontend of the site in one language and still keep most of the backend in English (or another language of your choice).
  
  You can use the standard Languages page to choose the language of the admin pages.