Here two examples of two negative clauses:
He neither approved my decision, nor did he approve yours.
He didn't approve my decision, nor did he approve yours.
Which variant is right and which is wrong? Or are these variants equivalent?
Here two examples of two negative clauses:
He neither approved my decision, nor did he approve yours.
He didn't approve my decision, nor did he approve yours.
Which variant is right and which is wrong? Or are these variants equivalent?
He neither approved my decision, nor did he approve yours.
Because the two boldfaced chunks have non-parallel constructions (different grammatical structures), the above sentence is incorrect.
On the other hand, these correct sentences all equivalently convey the quoted sentence's intended meaning:
He approved neither my decision nor yours.
He neither approved my decision nor approved yours.
(There's no good reason to write this sentence unless you are trying to say something like “He neither approved my decision nor disapproved yours” instead.)
He did not approve my decision; neither/nor did he approve yours.
He did not approve my decision; he did not approve yours either.