Spell check is either written into the app or it is not. It is on an app to app bassis. If it is written in, then within the application and with a document open go to Edit menu >> Spelling >> Check Spelling.
If this is not functional globally, try rebuilding LaunchServices.
Launch /Utilities/Terminal and copy & paste this at the command line to rebuild LaunchServices:
Code:
/System/Library/Frameworks/ApplicationServices.framework/\Frameworks/LaunchServices.framework/Support/lsregister \-kill -r -domain local -domain system -domain user
Then press return. Wait until terminal returns to the command line. Quit Terminal. After that, log out and back in or restart. Let us know.