by Everyone knows that every localized wordpress pack you download, usually, will use its own language in its back-end (admin a.k.a. wp-admin) or front-end user interface. Ex: If I download Indonesia-enabled wordpress, the user interface will use Indonesian as its default language. However, sometimes, with that localization, it makes the user interface not as user-friendly as in its original language (English), especially for the back-end section.
In this situation, we could switch back to use English for our wordpress back-end using a plugin called Plugins Language Switcher. With this plugin, we could switch our back-end language easily, just like changing the wordpress configuration sets.
For complete instruction of installation, just go to the main plugin page 🙂
very simple but i do not know it, thanks for the information