??(??)?? ????????????, ???????????? ???? '?? ????'???? ??, ?? ?????????? ???????????????? ?????? ???? ????????.  The two most commonly encountered grammatical ideas where this happens is when conjugating previously or present tenses. For examples:?? ???? ??????, ???? ???? ???? ?? ??? ??????.???? ????? ???? ???? ?? ?? ???? ???? ??? ?????? ????????