what did they sell
what do they sell
pro:int mod pro:sub v
what did they sell ?
w ʌ t WORD_BOUNDARY d ɪ d WORD_BOUNDARY ð eɪ WORD_BOUNDARY s ɛ l WORD_BOUNDARY
w h a t WORD_BOUNDARY d i d WORD_BOUNDARY t h e y WORD_BOUNDARY s e l l WORD_BOUNDARY