Is criterions a valid plural for criterion?

Dictionary.com says it is, but Oxford does not confirm or reject it.

  • 18
    NO! The fact that many people use the plural criteria loosely when they're only talking about a single criterion doesn't mean we can all play fast and loose with basic grammar. Commented Feb 15, 2012 at 23:28
  • 4
    Although I can understand the "vote to close" on the grounds of "general reference", I agree with @Henry this question raises an interesting issue. Arguably the main reason why criterions is so uncommon - despite superficially being the "natural" choice - isn't so much because we're all careful to "get it right". It's because we usually use the plural - as with data, probably many people don't even realise it is a plural (they think [it's] like sheep :) Commented Feb 16, 2012 at 3:16
  • 1
    @FumbleFingers: "data" plural in Latin, but in English it is singular, namely, a collective (non-countable) noun, which, as you noted, we use almost exclusively over "datum" which is nowadays a somewhat pretentious synonym for "data point". Insisting that "data" is an English plural countable noun is an instance of hyper-correctness. Commented Feb 16, 2012 at 8:14
  • 2
    @HexagonTiling Scientists and technologists routines employ data in the plural, for they construe it to be a count noun not a mass noun. Those averse to datum as a singular may use data-point for a singular form. Those who use data as a mass noun and hence singular sometimes use data-sets for a collective plural.
    – tchrist
    Commented Feb 16, 2012 at 12:59
  • 1
    Not exactly the same question, but: There is only one / Criterion. / Folks inferia / Say "one criteria".
    – MT_Head
    Commented Jul 10, 2012 at 1:23

5 Answers 5


If you use a word like criterion anywhere you are on the safe side by using the Greek plural, criteria. People who understand the former will get the latter, and vice versa.

Moreover, criterions is really not common according to google n-grams.

  • 1
    @Henry: you mean 'criterions' vs 'criteria', right?
    – Mitch
    Commented Feb 15, 2012 at 23:42
  • 1
    @Mitch: No. I think I meant what I said. Follow my link to check.
    – Henry
    Commented Feb 15, 2012 at 23:58
  • 2
    @Henry: yes, 'criteria' is the more common term than either, but the appropriate comparison would be with 'criterions'. Those two are the suggested plurals of 'criterion' and so '-ia' and '-ions' should be compared? What is the relevance of comparing the frequency of usage of the singular '-ion' with the plural '-ion' (as you say in your comment)?
    – Mitch
    Commented Feb 16, 2012 at 1:44
  • 2
    A. It is interesting. B. If the Greek based plural criteria is more common than the singular criterion and sometimes used in its place then the potential plural criterions will be uncommon, in the same way that the Latin based plural data being more common than datum suggests that datums is uncommon.
    – Henry
    Commented Feb 16, 2012 at 1:50
  • 4
    The OED gives the plural 'criteria', but comments ‘less commonly -ons', with one supporting citation from 1788. Only those with a pioneering spirit might be advised to use it. 'Criterion' is a Greek word rather than a Latin one, but the possibility that it might one day go the way of 'agenda'/'agendas' cannot be excluded. Commented Feb 16, 2012 at 8:46

Let me emphatically echo FumbleFingers' comment: NO!

Get It Right!

The plural form of criterion is criteria:

Decisions on whether to close schools are based on three criteria: (a) financial saving; (b) condition of the buildings; (c) educational provision.

People often confuse the singular and plural forms of this word, so if you need to use it in the singular be careful to use the correct form:

The only criterion for being accepted into the program is that you should have a bachelor’s degree in a relevant subject.


(I’ll add this somewhat meandering discussion as an answer to bring together in one place my various comments posted elsewhere.)

Let me add that the regularized -ion > -ions inflection in English for Greek 2nd-declension nouns instead of the Greek *-ion > -ia is comparatively rare. The OED attests only four instances of this that I can discover:

  1. criterions from a single 19th century citation
  2. ganglions from several 18–19th century citations
  3. parhelions from several 17–19th century citations
  4. stephanions from a single 19th century citation

Then again, any such noun is pretty rare in English. I think the only even moderately commonplace Greek -ion word apart from criterion is the medical term ganglion, and it too was historically on occasion given a regularized English plural, even though ganglia is now standard.

There are just not that many -ion nouns in English that come from Greek nouns. An OED search looking for English headwords ending in -ion and derived from Greek uncovers only 96 terms, and some of these do not count. For example, although ion is indeed < Greek ἰόν, that was the neuter present participle of ἰέναι to go.

If you relax the language of origin restriction, searching for -ion nouns in English headwords returns around 6900 terms, showing how uncommon the Greek ones actually are.

Most Greek -ion words occur in technical English, where retention of classical inflections is always higher than in the general populace, a well-documented phenomenon of ‘precisionist technicalese’, as it were. Only criterion alone is moderately commonplace outside technical circles, although a scant few other -on words do occur, like phenomenon in the previous sentence. The rest are all technical terms such as anthemion, aphelion, hapax legomenon, idolon, lepton, mitochondrion, noumenon, polyhedron, and taxon.

In computational linguistics, all the popular stemmers and lemmatizers (with one still-unpublished exception) do a distressingly poor job on technical writing, because they are ignorant of the classical inflections specialists continue to use with technical terms. The biomedical literature is particularly rich in Greek terms, and computer programs attempting natural language processing on these corpora must be specially trained to handle things like stoma, stomata if you expect to unify down to common lemmas.

The route by which these Greek words were introduced to English is not uniform. It may be directly from Greek; it may have first gone through Latin to get here; and it may have spent a time on holiday in France or even in Germany before finally making its way to us. For some words, such as parhelion for example, more that one route of origin applies. This multi-sourcing has led to a plethora of alternate forms. Here’s one example from the OED of how confusing the historical record of forms can be:

  • α. 15–16 parelii (plural), 16 parelios, 16 parelius, 16 parhelius, 17 parhelii (plural).
  • β. 16 parahelii (plural), 16 parelias (plural, irreg.), 16 parelion, 16 parhelia's (plural, irreg.), 16 parrhelions (plural, irreg.), 16– parhelion, 16– parhelions (plural, now rare), 17 parelium, 17 parhelium, 17– parhelia (plural).
  • γ. 16 parelies (plural).

As I mentioned in a comment to Barrie, the OED also attests a Latinized form of the singular criterium to go with the Greek criterion, with three citations one from each of the 17–19th centuries and starting with John Donne. Both forms conveniently become criteria in the plural.

There is however another, much more recent sense of criterium in contemporary English. The crowd-sourced Wiktionary entry gives this sense as

  • (bicycle racing) A mass-start road-cycle race consisting of several laps around a closed circuit, the length of each lap or circuit ranging from about 1/2 mile to about 1 mile.

Apparently, the plural for this particular sense is always criteriums, as grating as that may be to some ears. The crowd-sourced Wikipedia entry also gives the abbreviation crit for the circuit race, but I can find no history of the origin of this criterium for this sense.

Long-term stability of classical inflections in English plurals is dubious. Most eventually get regular forms in English, but this takes much longer if it is only a technical term used by specialists. In words of common usage, there is often a reanalysis of the classical form to better match the native form. On the other hand, technical literature is now more accessible than ever before, and this may interfere with regularization moreso than in previous centuries.

For example, data is often reanalysed to be a singular instead of a plural. This becomes a problem if it is to be used as a count noun instead of mass noun, since that would lead to the double-plural *datas, which has caused the more regularly behaving dataset and datapoint to spring up to work around that particular problem. Since we now have workable alternatives to address the mass- vs count-noun problem, I begin to doubt datum/data will be around that much longer in even technical English. No harm done, of course.

Similarly, casual speakers and writers, especially in newspapers and nontechnical magazines, are often found using bacteria and phenomena in the singular. You need only check the prevalence of ‘a bacteria’ or ‘this bacteria’ in uncurated, crowd-sourced Wikipedia to see how commonplace such errors are.

Finally, I should note that occasionally both forms persist, potentially with different nuance, such as a multidimensional array having several indices but a book having multiple indexes. It wouldn’t surprise me if casual speakers wrote ‘a criteria’ just as they so often write ‘a phenomena’ or ‘a bacteria’, unaware of or unconcerned with the chalkboard-scraping effect this has on some of us.

However, it seems to me that anyone conscious enough of the root lemma in -ion will choose the classical inflection rather than selecting the courageously regular ?criterions, let alone the Latinized ?criteriums (apart from the race).

  • 2
    Don't you mean “if you expect to unify down to common lemmata”? ;-) (And there is of course at least one other fairly non-technical -on word: lexicon.) Commented Aug 13, 2014 at 23:38
  • @JanusBahsJacquet Gee, now look what my Cerberus-trolling pulled in! :)
    – tchrist
    Commented Aug 13, 2014 at 23:39
  • @JanusBahsJacquet Worse is that the “still unpublished exception” no longer meets those criteria, as it has been published. However, my aversion to self-promotion precludes replacing that with a link to the paper.
    – tchrist
    Commented Aug 13, 2014 at 23:47

According to the Merriam-Webster dictionary, criteria and criterions can both serve as plural to the singular criterion. Here's the link.. http://www.merriam-webster.com/dictionary/criterions


Is criterions a valid plural for criterion? In a hundred years it might be, with the tendency towards anglicizing everything, but not now. If your native language is not English, then just take it from native speakers that criterions sounds to their ear as unpleasant as the proverbial fingernails on the blackboard.

"Criterions" does, however, sound like it might be a great name for a ball team...:)

  • @jwpat7: Thanks for the edits/corrections. Commented Mar 13, 2012 at 23:39

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