nan tte itteru ka wakaranai
nan tte itteru ka wakaranai .
n a n WORD_BOUNDARY t t e WORD_BOUNDARY i t t e r ɯ WORD_BOUNDARY k a WORD_BOUNDARY w a k a r a n a i WORD_BOUNDARY
n a n WORD_BOUNDARY t t e WORD_BOUNDARY i t t e r u WORD_BOUNDARY k a WORD_BOUNDARY w a k a r a n a i WORD_BOUNDARY