The Judiciary also uses a special type of monitoring through the General Inspection Office and Bureaucratic Justice Court. Additionally, either of the three powers have internal supervision mechanisms.
"Either" in the above paragraph is used for more than two items (three powers). Is it grammatical?
You've asked two questions here; one in your title:
Can “either” be used for more than two items?
and one in the body of your question:
Is this use of “either” correct in the above paragraph?
Catija has (correctly, in my opinion) given an answer to the second question. I'd like to answer the first: It depends.
As one grammar blogger wrote:
When used as a conjunction, “either” implies one of two or more elements. However, if it’s an adjective (meaning “one and/or the other”) or a pronoun (meaning “the one or the other”), then “either” implies one of two only.
The Free Dictionary has a usage note:
The traditional rule holds that either should be used only to refer to one of two items, and that any is required when more than two items are involved: Any (not either) of the three opposition candidates still in the race would make a better president than the incumbent. But reputable writers have often violated this rule, and in any case it applies only to the use of either as a pronoun or an adjective.
As for those aforementioned "violations," you can find several of them by going to Google Books and searching for "any of the three". When I did that, I noticed that several of the hits were from the 19th century, which made me wonder if either of the three was not considered the grammatical misdemeanor a century or so ago that it is today, a theory that seems to be supported by this Ngram:
I agree that "either" as a conjunction is helpful when multiple options follow. If I say, "I'm visiting Europe, and I want to go to London, Paris, Athens, Budapest, Stockholm ...", it begins to sound like an ambitious and perhaps superficial trip. But if I end it with "... or Rome.", you will then realize that it is not superficial; I'm still deciding which one to go to. In this case inserting "either" before "London" would have served the useful function of preventing that confusion.
No - but the problem is your example sentence.
In your sample, you'd need to use "all":
Additionally, all of the three powers have internal supervision mechanisms.
You need an inclusive word that means "all" or "each".
Either is problematic because that's not what the sentence is saying. "Either" allows you to choose between options.
You can have either soup, salad, or breadsticks.
This is a perfectly acceptable construction. It means you can only have one of the three.
But it would be incorrect to say:
Additionally, either of the three powers have internal supervision mechanisms.
Because it implies that not all of the powers have internal supervision mechanisms, which they certainly do, so "all" is required in this case.
"Either of the three" sounds wrong to my native ear.
But I wouldn't say that about a case such as
"There were no knives, no forks, and no plates either."
That doesn't sound wrong, insofar as one can reasonably parse it to be about two alternatives: on one hand, knives and forks; on the other, plates. But it does sound awkward, because the reader may be unclear as to whether it's that two-way alternative that the author has in mind or the three-way alternative.
