without kavana the neder/shavua is invalid, as ??? ??? ????? ?????
In all cases? Do we never say that ????? ???? ???? ??????
nedarim has been a while for me, but I’m recalling the 4 cases which don’t need hatara (nidrei zeruzin, etc.), and those were all cases where it is apparent to other people that you don’t mean it, if they know what is going on. Aren’t they?
see eg. the first ?? on 21a