Multilanguage In Drupal
If your language is not already added, you can do it in this interface admin/config/regional/language/add
You have to check that your new language is activated in the languages manager admin/config/regional/language 
Check that this modules are activated : Local, i18n
In your content type manager, check that multilingual settings tab exist
In this tab, choose the elements suitable for your case
In Publishing options tab, check that multilingual support is activated