Common Mistakes with the Plural of Criterion

If you have ever written a business report or an email and hesitated between criterion and criteria, you are not alone. The most common mistake is using criteria as a singular noun, but the correct singular form is criterion, and criteria is the plural. This guide explains the difference, shows you how to use both forms naturally in writing and conversation, and helps you avoid the errors that trip up many professionals.

Quick Answer

Criterion is singular (one standard or rule). Criteria is plural (two or more standards or rules). Do not write “this criteria” or “these criterion.” Use “this criterion” for one and “these criteria” for several.

Understanding the Singular and Plural Forms

Criterion comes from Greek and keeps its original plural ending -a. Many English words from Greek follow this pattern, such as phenomenon (singular) and phenomena (plural). In business contexts, you will often see criteria used as a collective term, but careful writers always match the number.

Formal vs. Informal Tone

In formal business writing, such as proposals, performance reviews, or policy documents, using the correct singular and plural forms shows attention to detail. In informal conversation or internal emails, some people use criteria as a singular, but this is still considered a mistake by careful readers. To sound professional, stick to the standard forms.

Email and Conversation Context

In an email to a colleague, you might write: “The main criterion for approval is budget alignment.” In a meeting, you could say: “We have three criteria to evaluate.” Using the right form helps you communicate clearly and avoids confusion.

Comparison Table: Criterion vs. Criteria

Natural Examples in Business Contexts

Here are examples you might use in real writing or conversation.

• Performance review: “The main criterion for promotion is consistent results.”
• Project selection: “We applied four criteria: cost, timeline, risk, and impact.”
• Vendor evaluation: “Each criterion must be scored separately.”
• Meeting discussion: “What criteria should we use to choose the software?”
• Email to team: “Please confirm that this criterion is still valid.”

Common Mistakes

Even experienced writers make these errors. Here are the most frequent ones and how to fix them.

Mistake 1: Using “criteria” as a singular

Incorrect: “The main criteria is customer satisfaction.”
Correct: “The main criterion is customer satisfaction.”

Mistake 2: Using “criterion” as a plural

Incorrect: “We have several criterion to meet.”
Correct: “We have several criteria to meet.”

Mistake 3: Mixing singular and plural verbs

Incorrect: “These criteria is important.”
Correct: “These criteria are important.”

Mistake 4: Overcorrecting

Some people avoid criteria altogether and use criterion for everything. This is not natural. Use the plural when you mean more than one.

Better Alternatives and When to Use Them

In some situations, you can replace criterion or criteria with simpler words. This can make your writing clearer, especially in internal communication.

• Standard – Use when you mean a single rule or expectation. Example: “The standard for approval is clear.”
• Requirement – Use for a specific condition. Example: “One requirement is a signed contract.”
• Measure – Use for a way to evaluate. Example: “We need a measure for success.”
• Guideline – Use for a general rule. Example: “Follow these guidelines for the proposal.”

When you need precision, especially in formal documents, stick with criterion and criteria. In everyday conversation, simpler alternatives often work better.

Mini Practice Section

Test your understanding with these four questions. Answers are below.

Question 1

Which sentence is correct?
A) This criteria is outdated.
B) This criterion is outdated.

Question 2

Fill in the blank: “We need to review all the ______ before making a decision.”
A) criterion
B) criteria

Question 3

True or false: “Criteria” can be used as a singular noun in informal emails.

Question 4

Choose the correct verb: “Each criterion (is/are) weighted equally.”

Answers

Answer 1: B) This criterion is outdated.
Answer 2: B) criteria
Answer 3: False. Even in informal writing, careful writers use “criteria” as plural.
Answer 4: is. “Each criterion” is singular, so use “is.”

Frequently Asked Questions

1. Is it ever acceptable to use “criteria” as a singular?

In very informal speech, some native speakers do this, but it is not considered correct in standard English. In business writing, always use criterion for singular.

2. What is the plural of “criterion” in British English?

It is the same: criteria. British and American English both follow the Greek plural.

3. Can I use “criterions” as a plural?

No. Criterions is nonstandard and rarely used. Stick with criteria.

4. How do I remember the difference?

Think of one criterion and many criteria. The word criteria ends with -a, like data (plural of datum). This pattern can help you recall the correct form.

Final Tips for Real Writing

When you write a report, proposal, or email, take a moment to check whether you are talking about one standard or several. If it is one, use criterion. If it is more than one, use criteria. This small habit will make your writing more accurate and professional. For more help with confusing plurals, visit our Confusing Plurals section. You can also explore Common Plural Forms for other patterns. If you have questions, check our FAQ or contact us.