I don't know sweetheart
I do know
pro:sub mod v
i don't know sweetheart .
aɪ WORD_BOUNDARY d əʊ n t WORD_BOUNDARY n əʊ WORD_BOUNDARY s w iː t h ɑː t WORD_BOUNDARY
i WORD_BOUNDARY d o n ' t WORD_BOUNDARY k n o w WORD_BOUNDARY s w e e t h e a r t WORD_BOUNDARY