but what had happened
but what have happen
conj pro:int aux part
but what had happened?
b ʌ tʰ WORD_BOUNDARY w ɒ tʰ WORD_BOUNDARY h æ d WORD_BOUNDARY h æ pʰ ə n d WORD_BOUNDARY
b u t WORD_BOUNDARY w h a t WORD_BOUNDARY h a d WORD_BOUNDARY h a p p e n e d ? WORD_BOUNDARY