Either vs. Neither
Either and neither normally organize choices involving two alternatives. Either presents one or the other (or appears in either…or), while neither rejects both (and appears in neither…nor); negative-sentence uses of either need separate treatment.
Use either for one of two alternatives or either…or; use neither for not one and not the other, commonly with neither…nor.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| one of two alternatives is acceptable or possible | either | Use “either,” including the “either … or” pattern. |
| both of two alternatives are rejected | neither | Use “neither,” including the “neither … nor” pattern. |
| a second negative item is added after an already negative statement | either can occur after the negative | Do not automatically replace negative-sentence “either” with “neither.” |
Quick tests
Meaning / construction test
Are you selecting one of two alternatives, or rejecting both?
If yes: Use “either” for one-or-the-other and “neither” for not one and not the other.
If no: If the sentence is already negative, remember that “either” has an additional negative-polarity use; agreement can also depend on the construction.
Caveat: Agreement and polarity can vary with construction, so the pair should not be reduced to a single substitution rule.
Examples
Either route will take us to the station.
“Either” means one or the other of two choices.
Neither route is open today.
“Neither” rejects both alternatives.
I do not like the blue option, and I do not like the red one either.
After an existing negative, “either” can add another negative item.
Further guidance
Number Boundary
Both words have construction-specific agreement patterns, so verb number can depend on the structure and register.
Polarity Boundary
Either can also appear after a negative to add another negative item; do not replace every negative either with neither.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Either … or… (opens in a new tab)Cambridge Dictionary · Either…or as a two-choice construction and its contrast with neither…nor
- Neither, neither … nor and not … either (opens in a new tab)Cambridge Dictionary · Neither for negative reference to two people or things