Jeff Atwood ♦ has just posted something that I'm confused about

Stack Overflow, due to its size, has some unique problems. One of those is flags

I'd say that those and flags are both in plural, however shouldn't is be plural too? It means, shouldn't it be

Stack Overflow, due to its size, has some unique problems. One of those are flags

I think it's right, because he's a native English speaker, but I'm just not sure why. Or is it just a mistake?

  • 1
    "It depends on what the meaning of the words 'is' is." –Bill Clinton Commented Aug 9, 2011 at 17:21
  • ?? What are you refering to?
    – genesis
    Commented Aug 9, 2011 at 17:26
  • 3
    Just to add to the other answers: you can analyse the sentence as One of those [problems] is [the problem of] flags.
    – Jon Purdy
    Commented Aug 9, 2011 at 19:10

5 Answers 5


Those is plural, yes, but "is" grammatically agrees with one in this case.

The sentence is something like this:

Stack Overflow, due to its size, has some unique problems. One {of those [problems]} is flags.

The part between [-] can be omitted to avoid repetition. The part between {-} can be omitted to explain the agreement.

So it could become: "One is flags".

EDIT: I'd like to add that the sentence "One of those is flags" written by Jeff, is perfectly fine. It's not nonstandard or ungrammatical. It's correct in English.

Like I said in the comments, "flags" is treated as a general noun, not as a plural of many objects. It's like saying "One of those is the flagging system".

  • I wonder whether the sentence would still hang together if the writer were referring to "flags" as the banner, not "flags" as the programming term for a boolean switch?
    – Tom Auger
    Commented Aug 9, 2011 at 14:25
  • @Aleanno - but, what is correct: flags are a problem or flags is a problem. So, yes is agrees with one, but can one agree with plural?
    – Unreason
    Commented Aug 9, 2011 at 14:26
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    @Unreason: the sentence is perfectly acceptable. It seems wrong to you, but it's not. "Flags" is treated as a "content-noun" in this case, not many objects in series. "Flags are a problem" is a different sentence comparing it to the Jeff's one, I don't think we can really compare it. What do you mean with can one agree with plural? The sentence is "One problem is [flags]" as in the flagging system.
    – Alenanno
    Commented Aug 9, 2011 at 14:33
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    @genesis: The thing is he's not saying flags as plural, he's mentioning flags as a concept, a whole. It's like saying "The concept [of flags] is a problem."
    – kba
    Commented Aug 9, 2011 at 14:36
  • @Aleanno, that interpretation I wrote in my answer, too: [flags] = the flagging system = the flagging concept which are singular. The only remaining question is: is it grammatical to refer to ”the flagging system” with unquoted word flags? (what is ”content-noun”?)
    – Unreason
    Commented Aug 9, 2011 at 14:38

Let me highlight the sentence as :

One (of those problems) is flags

The "is" agrees with the "One" in this case.

  • The "is" agrees with the "One" in this case. this is part I wanted to know :) Great, thanks. However, Englishman is wrong? (you edited my question)
    – genesis
    Commented Aug 9, 2011 at 8:39
  • 3
    I'm not sure if Jeff is from England which is what "Englishman" means. So I changed it to native speaker.
    – JoseK
    Commented Aug 9, 2011 at 8:53

I think that the main reason this sounds wrong is that the word ”flags” is used actually to refer to ”flagging system” or ”flagging concept”, singular. If such substitution is made, there are no problems with the original.

Alternatively, rewriting it like

One of those is related to flags.

seems (to me) more grammatical compared to the original (meaning is changed though; maybe caused by is closer to original intention).

EDIT: After opening a new question regarding this subject I should correct myself - there is nothing ungrammatical in the original line and the improvement I propose is just the matter of style.


Note that flags is not exactly plural but it is a feature (not mutiple features , not a plural.)

  one is typo

  One is 'flags'  

  One {Among these} is 'flags'

  One {of these} is 'flags'

That is how it happens!


(I may be off base here, but I don't believe so, and this hasn't been addressed so I'm adding this answer.)

The of those part of

One of those is flags.

is really a substitute for there being a problem with the site, not a direct reference to flags. Therefore you can substitute:

One problem is flags.

Here's it's easy to see that is agrees with one problem, and that whether or not the word that follows is singular or plural is irrelevant. These sentences are all fine:

One problem is a giant wildebeest in the back seat.

One problem is the twenty-two wet sponges blocking the door.

One problem is goats in my pants.

  • 1
    Or "One of the problems is people focussing on the two words in italics, rather than the whole sentence.". Commented Aug 9, 2011 at 15:22

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