either

ei|ther [ `iðər ] function word, quantifier ***

Either can be used in the following ways:

in the expression either...or:

Students could choose either French or Spanish.

You can either come by bus or take a taxi.

as a determiner (followed by a singular countable noun):

a long room with a door at either end

as a pronoun:

Olive oil and corn oil are both fine, so you could use either. (followed by of ):

Does either of you speak Chinese?

as an adverb (in negative sentences):

Jerry wasn't there either.

When either is the subject of a sentence, it is usually used with a singular verb:

Is either of them at home? But in spoken English a plural verb is sometimes used:

Are either of them at home?

1. ) one or the other of two people or things, especially when it does not matter which:

Check or credit card you can use either.

Applications are welcomed from people of either sex and any age.

either of: It was a long time before either of them spoke.

a ) either...or (...or) used for showing two or more possibilities or choices:

You must answer either yes or no.

You can contact us either by phone, by e-mail, or by letter.

When there's a crisis, they either do nothing or do something totally useless.

b ) either...or used for saying that one of two things has to happen or be true:

Either you come with us, or you stay at home with your mother.

Either he forgot about the meeting or he deliberately stayed away I don't know which.

c ) either way used for saying that it does not matter which of two things happens or is true, because the result will be the same:

Maybe the boy was really sick, or maybe he was just exhausted either way they would have to stop.

2. ) used in negative statements referring to both of two people or things:

Jackie could play the piano and sing, whereas I couldn't do either.

Most of the troublemakers were not fans of either team.

either of: I didn't like either of the candidates.

=> ALSO

a ) used for adding that a negative statement is also true of another person or thing:

It's a problem I can't solve, and I don't think anyone else can either.

We tried another method, but that didn't work either.

b ) used for adding a negative statement that emphasizes how good, bad, impressive, etc. something is:

He did a superb job, and he didn't have any help either.

c ) me either AMERICAN SPOKEN used when someone else has made a negative statement and you mean it is also true of you. This is considered to be incorrect by speakers of British English who would say me neither:

I don't like horror movies. Me either.

either side/end/hand etc.

each of two sides/ends/hands, etc.:

Her parents were sitting on either side of her.

There were stairs at either end of the hall.

Pierce entered the room carrying a briefcase in either hand.