what happened when we walked
what happen when we walk
pro:int v conj pro:sub v
what happened when we walked ?
w ʌ t WORD_BOUNDARY h æ p ə n d WORD_BOUNDARY w ɛ n WORD_BOUNDARY w iː WORD_BOUNDARY w ɔː k t WORD_BOUNDARY
w h a t WORD_BOUNDARY h a p p e n e d WORD_BOUNDARY w h e n WORD_BOUNDARY w e WORD_BOUNDARY w a l k e d WORD_BOUNDARY