Hmm from the way you've set it up you could potentially do this :
On button clicked, set another GV to true i.e. GV_Playing
Then while GV_Playing is true, if tag "word" is not playing (inverted isplaying) then play "incorrect", set GV_Playing to false and call the function. If "word" is playing then it will call the function on "word" ended anyway, and set GV_Playing to false.