“Criteria” – singular or plural?

by Jakub Marian

Tip: See my list of the Most Common Mistakes in English. It will teach you how to avoid mis­takes with com­mas, pre­pos­i­tions, ir­reg­u­lar verbs, and much more.

The media seem to have been plagued with expressions like “the criteria is” lately. Unfortunately, such expressions are incorrect, because “criteria” is a plural noun; using it as a singular noun is essentially the same as saying “a houses is”.

If “criteria” is the plural, what’s the singular? The word is based on the Greek pattern -on → -a, so the singular form is criterion. For example:

The main criterion is as follows. (correct)
The main criteria are as follows. (correct)
The main criteria is as follows. (wrong)
That’s a very important criterion. (correct)
Those are very important criteria. (correct)
That’s a very important criteria. (wrong)
This criterion was decided upon by the committee. (correct)
These criteria were decided upon by the committee. (correct)
This criteria was decided upon by the committee. (wrong)
There’s only one criterion. (correct)
There’s only one criteria. (wrong)

One could argue that since what is considered correct is decided by usage, saying “a criteria” should be acceptable (as it has become somewhat widespread). However, no major dictionary or manual of style endorses such usage, and most educated native speakers find it wrong, so there is no good reason to use “criteria” as a singular noun.

By the way, if you haven’t read my guide on how to avoid the most common mistakes in English, make sure to check it out; it deals with similar topics.