?? ???? ???????? ?????? ????????? ?? ??????.???????? ??(?? ???? ???? ??, ?????? ????? ?????????????????. ??” ????? ?????? ???? ???????? ?????? ?????? ???????? ?????? ?? ????.If a grammatical principle that is extra to ????is really a vowel ??and there's no other alternative apart from a vowel ??then that grammatical theory can not be extra to ?