???? & ?????? ???????? ???????? ???? ?? ??? ?? ???? ?? ????????The 2 most typical grammatical concepts wherever this happens is when conjugating in past times or present tenses. For examples:- ???? ??: ??, ??, ??(??, ???????? ??), ??????, ??, ????????????? ???? ?????????????? ??????????????? ???? ?? ????????????????? ???????? ?????? ???? ??????????