???? & ?????? ???????? ???????? ???? ?? ??? ?? ???? ?? ????????The 2 most frequent grammatical ideas exactly where this happens is when conjugating prior to now or current tenses. For examples:?? ???? ??????, ????????????, ???? ???? (???????? ??)?????? ???? ?? ???? ??? ?? ?? ?????? ?????? ?????? ???? ???????? ?????????? ?????????????????? ???? ???