Take the 2-minute tour ×
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It's 100% free, no registration required.

Does “either . . . or” apply to only two options?

For example, can I say, “It can provide either 100, 150, or 400 amps of power”? Or should it just be “It can provide 100, 150, or 400 amps of power”?

share|improve this question
Amps (amperes) are not units of power. Amps are units of electrical current. It might be okay to say Amps of electricity (current is electrical flow in a conductor). –  Tom Ferrell Feb 22 at 23:19
add comment

4 Answers

up vote 9 down vote accepted

First of all, it's common usage, that is, in native English speech, to refer to multiple choices using either, but it's not entirely grammatical (from a prescriptivist's point of view). The definition of either is:

Each of two. [from 9th c.]  
One or the other of two. [from 14th c.]  

Note that I say it's common in informal speech and usage, but probably not for formal contexts.

An entire page of Wikipedia was devoted to this word, and the definition given was:

Either/or means "one or the other." Its usage, versus the simple or structure, is often for emphatic purposes, sometimes intending to emphasize that only one option is possible, or to emphasize that there are only two options.

Thus, it depends on what the context is. If in speech, then either would be appropriate. If however, in a formal context (business letter, etc.), then using either for multiple choices would be inappropriate.

share|improve this answer
This answer neglects that the OED attests that either sometimes means “any one of more than two”. It is not a common usage, however, and most copyeditors frown on it. –  tchrist Sep 2 '12 at 19:10
Note that whether follows similar rules. –  user61979 Feb 21 at 16:48
add comment

Either is used where one is required and there are multiple options, usually two. It can be used for more than two but it is most often is used for only 2 options.

In the sentence you're asking about you could say:

It can provide either 100, 150, or 400 amps of power

But it will sound better if you say

It can provide 100, 150, or 400 amps of power

because saying either makes the options sound limited even though there are multiple options.

share|improve this answer
add comment

You can use "either" for more than two options, but what do you want to say? The first example (with "either") implies that you would need a different power source to provide each one of the outputs. "Either" emphasizes exclusive possibilities. The second example implies that it (i.e. the same power source) can provide all three options - 100, 150 and 400 amps. In context, though, either example could be construed to include both meanings.

share|improve this answer
add comment

... while either coordinations are characteristically binary, multiple ones like either Kim, Pat or Alex are also possible. 1

Although commonly stigmatized, (a multiple correlative like either) can add clarity to constructions whose complexity might otherwise cause confusion. For this reason, such constructions are sometimes used even in careful written English, eg in the rubric of an examination paper:
Candidates are required to answer EITHER Question 1 OR Question 2 OR Question 3 and 4. 2

share|improve this answer
add comment

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.