Neither is used as a negative part. For example:Neither Jake nor kate can help me to solve my problem. Either is the same as "or" Mark is going to visit either Italy or Spain next week

Neither =is close to= not either There are two muffins left. Help yourself to either one. We must choose. We must go either left or right. Either cross the road or don't. Standing in the middle is not an option. The two muffins left are lemon & blueberry. I don't like either flavour. The two muffins left are lemon & blueberry. I like neither flavour. . Neither of the two boys wanted another muffin. A:Well which one is it? You must either walk or take the bus. B: Neither, I'm riding my bike.