你说的对 我认为应该是either ,如用neither应倒装为：
Neither do I know.
当neither表示“亦不”涵义时,其后的主谓语往往要倒装.例：
You did not see her,neither did I．
你没有看见她,我亦未看见她.
You will not go to Macau,neither will I．
你不想去澳门,我也不想去.
顺带一提,以上两句中的neither did I/neither will I 可说成nor did I/nor will I或and I didn't either/and I won't either．