Thank you for checking out my question. Even though I asked a similar question earlier, another confounding issue showed up here.
Is this sentence grammatically correct or, at least, acceptable?
Every one of them could not solve it.
I know that it should rather be written like;
None of them could solve it.
However, I failed to clearly point out what is wrong with this sentence. I would be delighted so much if you kindly give advice to me.
Thank you so much for your time!