Question

No one knows the password secret.(spot the error)​

Answer 1

Answer:

It should be 'to whom it belonged'. The sentence should read: I don't know to whom it belonged. When the relative pronoun is the object of the relative clause, we use whom instead of who. Note that, in this case, the preposition normally goes before whom

Answer 2

Answer:

error is No one knows,

it is nobody knews