"Either" is a positive word that marks a selection of two choices. "Neither" is a negative of "either" that marks a negation of two choices. EX: EITHER (you have a choice between two things) Please choose either the pencil or the pen. Either the cat or the dog ate the food. *Notice that "either" is used with "or". EX: NEITHER (none of the choices are good choices) Neither the cat nor the dog could have eaten the food. Neither the pen nor the pencil will be dark enough to draw the picture. *Notice that "neither" is used with "nor". This is a basic explanation that should give you a good idea of how to use either and neither and what they mean. If you have any other questions, please don't hesitate to ask. Good luck! :)

either - there is a choice between 2 things. Both could be correct or possible. neither - There is no choice. Both are wrong or not possible.