# The problem is threefold?

The problems are threefold.
The problem is threefold.

Which is the right way to use the -fold suffix?

Note - This question was previously asked by a user whose account has been suspended, so the question was auto-deleted. I'm re-posting now it because I think this is a valid question.

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According to Waiwai, this question was plagiarized--you might want to pull up the attribution – simchona Jun 21 '12 at 17:32
Who cares where it comes from? Has anybody noticed yet that there's a metaphor of folding involved? Things that are folded are separated in one sense and connected in another. That doesn't sit well with binary Singular/Plural. – John Lawler Jun 21 '12 at 17:37
@JohnLawler I didn't say delete it, I said to consider giving the original post credit. Another user was suspended for this – simchona Jun 21 '12 at 17:39
Alas, I have no knowledge of almost all individual users, and less interest in internal politics. – John Lawler Jun 21 '12 at 17:43
@FumbleFingers: simchona means "plagiarized by the suspended user"; (s)he's referring to waiwai933's answer to your question on meta, which explained the deletion of the original question as being because it "was plagiarized from another online forum." – ruakh Jun 21 '12 at 20:53

## 4 Answers

The actual question does not seem to quite compare like with like due to pluralization, e.g.

The problems are threefold.
Could seem to - possibly - mean multiple problems have 3 parts to each of them.

The problem is threefold.
One problem has three parts. Definitely just One problem (but with 3 parts).

The is and are are getting used based on the pluralization of problem, after all one can't have "problem are" or "problems is".

In practice both forms are basically usually used to mean the same thing, 3 parts to one thing.

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I have a problem with this question, and that problem is twofold. First, the question was already deleted, so why is it being reintroduced? Second, the title says "twofold," but the example sentences say "threefold" – that's inconsistent. (Truth be told, I don't have any problem with this question; I just made all that up to test Michael's postulate. It seems to work just fine, so I'll upvote his answer.) – J.R. Jun 22 '12 at 8:54

If I heard someone speak your first sentence, I would assume that there is a set of problems, and that each problem in that set is threefold. If I heard the second, I would assume that there is a single problem, and that this problem is threefold.

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I feel like something of a "fifth columnist" here, in that I didn't actually ask this question in the first place. But I agree grammatically that's a possible interpretation, per the final paragraph in my own answer. Semantically I feel it's less likely than the other two interpretations, but sadly we can no longer ask the original OP for his exact context. – FumbleFingers Jun 21 '12 at 17:03

I'm not sure how much light it sheds on current use, but I'm fairly sure the origin of the phrase was from physical craftsmanship. Leather, for example, folded over itself several times, is stronger than a block of the same depth. You can apparently do the same with metal; threefold bronze was a Roman metaphor for strength. [Aes triplex in Latin; the English word complex/complicate is from a similar root.]

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OED acknowledges the physical folding/pleating sense of words with the -fold suffix, but says they "serve also and chiefly as arithmetical multiplicatives". OED also say the "multiplied by" sense applied to ancient Greek & Latin equivalents, and the Teutonic precursor to English -fold, so I'm not sure I'd agree "the origin of the phrase was from physical craftsmanship". – FumbleFingers Jun 21 '12 at 21:04

Both forms occur - but for what it's worth, "is threefold" is more common

The difference is simply one of style/emphasis. The problem is threefold if you see it as a single problem with three "sub-components", or "aspects". If you think there are actually three distinct problems, you might feasibly say the problems are threefold - but I think this is clumsy phrasing, and would be better expressed by saying there are three problems.

Personally I think that when something - singular or plural - is described as threefold, this usually implies there are three aspects relating to one thing or group of things. Thus a third interpretation is possible, whereby the problems are threefold could refer to any number of problems, all of which share three particular characteristics.

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The problems are threefold for "There are three problems" is probably archaic (or pseudo-archaic), but not really clumsy. – Andrew Leach Jun 21 '12 at 17:23
@Andrew Leach: Well, the fact that my NGram shows a significant bias towards "is threefold" does rather suggest that most usages are in the context of a single thing [problem, whatever] having three aspects. And since that's my "default" understanding of how the word is used, anything that conflicts with it is "clumsy". I doubt it's really "archaic" though, since the plural form got started much later than the singular ("pseudo-archaic" is possible though). – FumbleFingers Jun 21 '12 at 19:42