You could correct errors using correction tape: basically pressed dry white-out atop the letter, assuming you lined it up correctly and pressed the same letter - you then type the correct letter. Of course for an important document like a resume you may want to retype the whole thing.

Also it wasn’t really a “printout” since you saw each letter as you typed it.

;) Your mission, should you choose to accept it, is to develop a "manual" typewriter that warns the user that they are about to make a spelling mistake, possibly keeping the whole word in a buffer until they handle the warning. The warning itself can be performed via any means, including but not limited to an electrical zap.