Solved How can I switch the languages in Kunena

That's very kind of you, but I don't want to spoil your vacations and..... I GOT IT !!!!!

Explanation : I did not install the Kunena Language Package correctly. I only installed the French package as I didn't want the rest of languages, but by doing so I forgot some important file apparently.
I just reinstalled everything, and it works just by refreshing (so at least I had the menu structure correctly set-up, which is already a small miracle !!!

Thanks for your support anyway, it makes me investigate some things when I was about to start looking at drupal

Good to hear! and have fun

However I am interested to know how to display Kunena menu (Index, Recent Topics, .... Search) as tabs above the forum windows instead of a simple menu. Just as it is in this current forum

You go to joomla admin panel( backend).
Go to Menu manager and create a new menu item in the menu you want. This new menu item has to be "menu item alias". From the required settings you choose your kunena forum and you 'll be ok!

This creates a regular menu, doesn'it ? What I want to have is a series of tabs above the forum windows just like here in this forum (see attachement)



Is this a special template for this ? I just use the default one and tried to place it in position 12 but it just displays a regular menu

Yes it creates a regular menu, but it also makes theese tabs visible when you click on your new menu item alias. Try it and you will see!

Oh, by the way you forgot to upload your attachement.