???? ???????(????)????????????? ???? ????????.If a grammatical basic principle which is extra to ????is often a vowel ??and there's no other option other than a vowel ??then that grammatical basic principle can't be additional to ????- ???? ??: ??, ??, ??(??, ???????? ??), ??????, ??, ????????????? ???????? ????, ???????? ?????? ????????? ?????????