اعتقد فيه خطا في القواعد لأن Either للجمل الايجابية مثل too ماتجي مع النفي
للنفي نستخدم Neither
Either" is a "positive" word because it refers to something that is real or true:
Either John or Bill is going to the meeting. No matter what, one or the other of them will be at the meeting.
"Neither" is a negative word: Neither John nor Bill is going to the meeting. No matter what, those two will not be at the meeting!
So in the sentence you give, we would not say "can't neither" because that would be a double negative. So we would say: I can neither dance nor sing.
And that is true about me: I can neither dance nor sing