he didn't see it
he do see it
pro:sub mod v pro:per
he didn't see it ?
h iː WORD_BOUNDARY d ɪ d n t WORD_BOUNDARY s iː WORD_BOUNDARY ɪ t WORD_BOUNDARY
h e WORD_BOUNDARY d i d n ' t WORD_BOUNDARY s e e WORD_BOUNDARY i t WORD_BOUNDARY