Neither vs Either - Do you know when do use which?

a year ago

Neither vs. Either
Question
When should I use neither and either, and how are they used?
Answer
Either and neither can be used in a few different ways, and can indicate different things. It depends on if you are using it as an adjective pronoun, conjunction or adverb.
When used as an adjective either indicates: one or the other of two people or nouns.
When used as an adjective neither indicates: not one or the other of two people or nouns.
In other words, neither means "not either."
The following example sentences show this use.
He can drive either car. (He can drive one or the other of the two cars).
He can drive neither car. (He can’t drive one, and he can’t drive the other of the two cars; he cannot drive either car]
When used as a pronoun either indicates one or the other.
When used as a pronoun neither indicates not one and not the other, or not either.
The following example sentences show this use.
My husband may wear either of the shirts to dinner. (My husband may wear one shirt or the other shirt).
My husband may wear neither of the shirts to dinner. (My husband may not wear one shirt, and he may not wear the other shirt; he may not wear either shirt).
When used as a conjunction either is used with or to indicate choices or possibilities.
When used as a conjunction neither is used with nor to indicate two or more people, things, actions, etc., which are both not true or as a double negative.
The following example sentences show this use.
I will eat either cake or cereal for breakfast. (I will choose one of the two options to eat for breakfast).
I will eat neither cake nor cereal for breakfast. (I will not eat cake and I will not eat cereal; I will not choose either of these two foods).
When used as an adverb either means "in addition" and is used after a negative statement. The following example sentences show this use.
The food is healthy, and not expensive either. (The food is healthy and in addition to that it is not expensive).
The movie is funny and it is not too long either. (The movie is funny in addition to being short).
In informal speech either and neither are used in the phrase me either or me neither to say that you agree with a negative statement someone has made. These two phrases mean exactly the same thing. The following example sentences show this use.
"I don't like this restaurant." "Me either.” (I also don’t like this restaurant).
"I would never go to Russia, it is too cold" "Me neither.” (I also would never go to Russia).
**PLEASE NOTE**
Whilst you might hear both either and neither in response to these negative statements above, “me either” is sometimes commonly used but widely considered to be grammatically incorrect. So, try to stick with “me neither.”