??(??)?? ????????????, ???????????? ???? '?? ????'???? ??, ?? ?????????? ???????????????? ?????? ???? ????????.  If a grammatical principle that is extra to ????is usually a vowel ??and there is no other choice aside from a vowel ??then that grammatical theory cannot be additional to ????- ???? ??: ??, ??, ??(??, ???????? ??), ??????, ??, ???????