Language translations are provided by customers. I show the file to be 99.99% translated except for words like ADMIN AIM and ALBUM
This would seem to me that there is no spanish equivelent or the words are the same in that language so if this is what your referring to not translated
If am not mistaken just like German there are different variations of spanish so the way different regions speak or write may influence here. Is this what you are referring to?
You can edit the spanish.php file in your languages subdirectory.