but then he frowned
but then he frown
conj adv:tem pro:sub v
but then he frowned .
b ʌ t WORD_BOUNDARY ð ɛ n WORD_BOUNDARY h iː WORD_BOUNDARY f ɹ aʊ n d WORD_BOUNDARY
b u t WORD_BOUNDARY t h e n WORD_BOUNDARY h e WORD_BOUNDARY f r o w n e d WORD_BOUNDARY