?? ?? ???? ?? ??????????????????? ????? ????, ??, ????, ???? ????, ????, ???? ?????? ???? ??????, ????????????, ???? ???? (???????? ??)???????? ???????? ????, ???????? ?????? ????????? ???????????? ???? ????. ???? The 2 most common grammatical concepts where by this happens is when conjugating in past times or existing tenses. For examples:?? ?????