Either is an adjective that is used to describe the inclusion of both possibilities in an argument.
It is placed before the noun it modifies and emphasizes that either of the possibilities is valid.
1. She brought either dress to the event.
2. If you have either of these keys, you can open the box.
3. I won’t satisfy either possibility unless absolutely necessary.
Be aware of the different uses of either when used as an adjective. It is important to recognize the context in which either is used to correctly interpret its meaning.
as a pronoun, 'either' is used to refer to one of two choices or possibilities previously mentioned or understood from the context.
'Either' can be used to refer to one of two things, people, or situations that have been mentioned.
Either of the options works for me.
I don't like either of the candidates.
Either is acceptable.
'Either' as a pronoun is often used with 'of' followed by a plural noun or pronoun. Avoid using 'either' when referring to more than two options; it is specifically for two choices.
As an adverb, 'either' is used for emphasis in negative sentences to indicate that a negative condition also applies to another subject or object.
'Either' can be used at the end of a sentence or clause to emphasize that what is said applies to more than one subject or object.
I don't like spinach, and my brother doesn't either.
She's not attending the meeting, and I'm not either.
He didn't pass the test, and she didn't either.
When used as an adverb, 'either' usually appears at the end of the clause. Avoid using 'either' as an adverb in affirmative sentences; it's used to emphasize negation.
as a conjunction, 'either' is used to introduce the first of two alternatives in a correlative conjunction pair 'either...or.'
'Either' can be used to introduce the first of two alternatives, usually followed by 'or' introducing the second alternative.
You can either stay or leave.
Either you fix this, or I will.
He will either come on time or not come at all.
Make sure to complete the 'either...or' structure; leaving it incomplete can create confusion. Avoid using 'either' with 'nor'; the correct pair is 'neither...nor.'