How to set the language of a post ?

Hello,

My site is multilingual En/Fr and I would like to set my posts in Fr.
But I don't understand how to do it.

I've Enable "Multi Language posts" in the settings.
But right now all my posts language are set to All and I don't know how to change it to Fr.

Could you help me ?

Joomla: 3.3.6
Easyblog: 3.9.19335

Regards,

Cynthia