The installed languages in the SharePoint server can be supported by the site which is specified by the owner of the site, so that users who navigate to the site can then change the display language of the user interface to any of these alternate languages.
Go to Site Actions => Site Settings => Language Settings.
You can see option Alternate languages.
Note: MUI should be enabled for the website otherwise you will get only the default language.MUI can be enabled by setting the property web.IsMultilingual=true.
The alternate languages can be determined by using the SharePoint 2010 object model.
Namespace: Microsoft.SharePoint Assembly: Microsoft.SharePoint (in Microsoft.SharePoint.dll)
Open Visual Studio 2010.