ClassiPress does not currently have a built in function to allow multiple languages at the same time. There are plugins which can do this, however I'm not aware of any right now that will work 100% accurately with the latest version of ClassiPress. I understand plugins such as WPML will work with older version of ClassiPress (v3.0.4) but these plugins are still not officially supported. For the moment, you can only choose to run the site in 1 language at a time unless you make modifications to allow multilanguage plugins to work.
