I recently was asked when to use neither/nor instead of either/or. The rule is pretty simple. You use either/or when you are talking about something in a positive sense. You use neither/nor when you are talking about something in a negative sense.
Remember either must be paired with or and neither must be paired with nor. Below are some examples of both pairs of words.
I like neither chocolate flavored ice cream nor vanilla. (Of course, this is not true. I love all flavors of ice cream.
There are neither dogs nor cats in my house, only birds.
Either come over here and talk to me or I will go over there and talk to you.
My son is either very sleepy or just plain lazy as he just fell asleep while he was eating his dinner.