Oh, sorry, I mis-read that!
See this WordPress doc page to setup WordPress in another language:
This is what you need to add to the
wp-config.php file for Spanish:
define ('WPLANG', 'es_ES');
If I remember correctly … in order for the Spanish translation to be used in Connections, the Spanish translation must also be set up and properly configured for WordPress…
If you do not have the MO/PO file for WordPress (not Connections) you can download them from here:
I might be easier for you to use this plugin instead to setup Spanish for WordPress: