I am trying to type a paper in spanish and I cannot change the spell checker to spanish, I got to inspector then check Espanol but it does not register and just returns to english or does not work am i forgeting to do something?
Language settings for individual documents are tied to paragraph styles. You will need to go to the text inspector > More & set it for each paragraph style. Right-click the triangle to the right of the style name in the styles drawer & redefine the style to the current selection.
You can change the system-wide language, but that won't affect any existing documents.