What Is the Plural of Criterion?
The plural of criterion is criteria. This is a direct, non-negotiable rule in standard English. Criterion is a singular noun that follows the Greek plural pattern, not the regular English -s or -es rule. You will almost never see criterions in formal or academic writing, and it is considered a mistake. If you need to talk about more than one standard or principle by which something is judged, the correct word is criteria.
Quick Answer
- Singular: criterion
- Plural: criteria
- Incorrect plural: criterions
- Usage note: Criteria is a plural noun and should be used with plural verbs (e.g., criteria are, not criteria is).
Why Is the Plural of Criterion Not “Criterions”?
The word criterion comes directly from Greek, where it follows a specific declension pattern. Many English words borrowed from Greek retain their original plural forms. Common examples include phenomenon (plural: phenomena), thesis (plural: theses), and crisis (plural: crises). The -on to -a shift is a hallmark of this group. While some Greek borrowings have gradually adopted regular English plurals over time (e.g., memorandum can be memorandums or memoranda), criterion has not. Using criterions will mark you as unfamiliar with academic or formal English conventions.
Formal vs. Informal Tone and Context
Understanding when to use criterion and criteria correctly is essential for clear communication, especially in academic and professional settings.
Formal and Academic Contexts
In research papers, business reports, grant applications, and official documents, precision is paramount. You must use criterion for one standard and criteria for multiple standards. Using criteria as a singular noun (e.g., “The main criteria is…”) is a common error that can undermine your credibility.
- Correct (formal): The primary criterion for admission is academic excellence.
- Correct (formal): Several criteria were used to evaluate the proposals.
- Incorrect (formal): The main criteria for selection is experience.
Informal and Conversational Contexts
In everyday conversation, emails to colleagues, or informal writing, the strict singular/plural distinction is sometimes relaxed. Many native speakers, even educated ones, use criteria as both a singular and plural noun in casual speech. However, this is not considered correct in careful writing. If you want to sound polished and precise, always maintain the distinction.
- Casual (acceptable in speech): What’s the main criteria for joining the club?
- Careful (better for writing): What is the main criterion for joining the club?
Comparison Table: Criterion vs. Criteria
| Feature | Criterion (Singular) | Criteria (Plural) |
|---|---|---|
| Number | One | Two or more |
| Verb agreement | Uses singular verb (e.g., is, was, has) | Uses plural verb (e.g., are, were, have) |
| Example | This criterion is difficult to measure. | These criteria are difficult to measure. |
| Common error | Using criteria as singular | Using criterions |
| Formality | Preferred in all careful writing | Required for plural; avoid as singular in writing |
Natural Examples
Here are examples that show how criterion and criteria are used in real-life situations, from emails to academic discussions.
Email Context (Formal)
Subject: Feedback on Project Proposals
Dear Team,
Thank you for submitting your proposals. We have reviewed them against the following criteria: budget feasibility, timeline, and innovation. Each criterion was weighted equally. Please note that the most important criterion for the final decision is alignment with our strategic goals. If you have questions about how these criteria were applied, please let me know.
Best regards,
Dr. Elena Rossi
Conversation Context (Informal)
Alex: So, what are the criteria for choosing a restaurant tonight?
Jamie: Well, the main criterion is that it has to be within walking distance. The other criteria are good reviews and vegetarian options.
Alex: Got it. So the distance criterion is the deal-breaker?
Jamie: Exactly.
Academic Context
In a research study, the inclusion criterion for participants was age over 18. The exclusion criteria included a history of certain medical conditions. The researchers carefully defined each criterion before data collection began. All criteria were published in the methodology section.
Common Mistakes
Even advanced English learners make these errors. Here are the most frequent ones and how to fix them.
Mistake 1: Using “Criteria” as a Singular Noun
Incorrect: The main criteria for success is hard work.
Correct: The main criterion for success is hard work.
Explanation: Criteria is plural, so it needs a plural verb (are) and cannot be described as “main” if there is only one. Use criterion for a single standard.
Mistake 2: Using “Criterions”
Incorrect: We have three criterions to consider.
Correct: We have three criteria to consider.
Explanation: Criterions is not a standard English word. The only correct plural is criteria.
Mistake 3: Mixing Singular and Plural in the Same Sentence
Incorrect: This criteria is important, but the other criterion are less so.
Correct: This criterion is important, but the other criteria are less so.
Explanation: Keep the number consistent. This and is go with singular criterion. Other and are go with plural criteria.
Better Alternatives and When to Use Them
Sometimes, using criterion or criteria can sound overly formal or technical. Here are simpler alternatives that work well in many contexts.
- Standard / standards: Use when the idea is about a level of quality. “The main standard for hiring is experience.” (Instead of “criterion”)
- Requirement / requirements: Use when the idea is about something that must be met. “One key requirement is a valid passport.” (Instead of “criterion”)
- Rule / rules: Use in informal or game-like contexts. “The first rule is to be on time.” (Instead of “criterion”)
- Factor / factors: Use when discussing elements that influence a decision. “Several factors influenced our choice.” (Instead of “criteria”)
When to use it: Stick with criterion and criteria in academic writing, formal reports, and professional evaluations. Use the alternatives in everyday conversation, emails to close colleagues, or when you want to avoid sounding stiff.
Mini Practice: Test Your Understanding
Choose the correct word (criterion or criteria) for each sentence. Answers are below.
- The most important __________ for this job is attention to detail.
- All the __________ for the scholarship have been published online.
- Each __________ must be clearly defined before the experiment begins.
- These __________ are not flexible; they must be followed exactly.
Answers
- criterion (singular, “most important” refers to one standard)
- criteria (plural, “all” indicates more than one)
- criterion (singular, “each” refers to one standard at a time)
- criteria (plural, “these” and “are” indicate more than one)
Frequently Asked Questions
1. Is it ever correct to say “criterias”?
No. Criterias is not a word in standard English. The plural of criterion is criteria, and it does not take an additional -s.
2. Can I use “criteria” as a singular noun in an email to a friend?
In very informal, spoken English, some native speakers do this. However, it is still grammatically incorrect. If you want to sound careful and educated, even in casual writing, use criterion for the singular. Your reader will notice the precision.
3. What is the plural of “criterion” in British English?
The plural is the same in both British and American English: criteria. There is no difference. The usage rules and common mistakes are identical.
4. How can I remember the difference between “criterion” and “criteria”?
Think of the word phenomenon (singular) and phenomena (plural). They follow the same Greek pattern. Another trick: criterion has the same number of letters as singular (both have 9 letters), while criteria has the same number of letters as plural (both have 8 letters). This is a simple memory aid.
For more help with similar tricky word pairs, explore our guides on Common Plural Forms or visit our FAQ page for answers to other common questions. If you have a specific question about singular or plural usage, check the Singular or Plural Checks section. You can also read our Editorial Policy to understand how we ensure accuracy in every guide.
