keyboard - some keys work other than default

Hello everyone,

since a while some of the very upper keys do not work; or function other. Eg. the sound control keys just work with fn key. Otherwise, the louthe and quite rkey doesn't wokt at all, and the sound lower key shows the desktop, And since then the right click doesn't work too. It is as if I am doing a lett click. I've added some new language to my mac and some keyboard settings are been changes I think. Any help please ...

Upgrading to ElCaptain hasn't changed anything!

Thanks