#1 is correct. You use this construct when you want to place an extra emphasis on the 2nd part. Otherwise, if you want to treat the part preceding the 'nor' with equal stress/emphasis as the part after the 'nor' than you would not use this construct. You'd say something like, "I don't see it as a good idea or that it's even possible". This 2nd form is probably more common. 2. Neither DO I see it as a good idea, nor do I believe that it's even possible. ('do' needed) 3. I neither see it as a good idea nor believe that it's even possible. (correct) #3 is slightly better than #2.