Either/or and Neither/nor

Either/or and neither/nor are pairs of correlative conjunctions that work together. They are used in these combinations only and cannot be mixed. In addition, the conjunction and should not be used with either or with neither.

I didn’t see either you and him.
I didn’t see either you nor him.
I didn’t see either you or him.

I saw neither you or him.
I saw neither you nor him.

Neither and nor, when used together, are not considered a double negative.

Note that all of these words can be used separately from one another; either and neither can act as pronouns and as adjectives:

Either of the options is fine. [pronoun acting as the subject]

Neither option is acceptable. [adjective modifying option]

When using correlative conjunctions, be sure to follow the principle of parallelism. See my Parallelism page for more information.