From where does the game get the information which language it will use

[Legacy_Tolkiens Padawan]

               I have created descriptions and names for objects that don't show up correctly now, instead the English versions are used. I have changed the dialog.tlk in the main folder of NWN. Could that cause it? How do I tell the game to use the German names and descriptions (I know I could place them all in the English text-box, but there must be an easier way, otherwise there would have been no need for multiple language boxes)? Thank you.
               
               

               
            

[Legacy_Shadooow]

               from the players dialog.tlk
               
               

               
            

[Legacy_Tolkiens Padawan]

               Thank you. Now that I searched for it in the Killer TLK Editor, I found the language button.
               
               

               
            

[Legacy_Shadooow]

               

Tolkiens Padawan wrote...

Thank you. Now that I searched for it in the Killer TLK Editor, I found the language button.

I dont think this works, it shows German for the english 1.69 dialog.tlk and changing it had no effect when I tried it in past.
               
               

               
            

[Legacy_Tolkiens Padawan]

               Well, that's weird as it works fine for me (the other way round, setting the German tlk, former showing "English" to "German").