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The Plural Forms of Words

The Quick Answer
The word plural means more than one in number. (It contrasts with singular.) The term plural can apply to nouns, adjectives, pronouns, and verbs. For example:

Word TypeExample in the
Singular Form
Example in the
Plural Form
NounCatCats
AdjectiveHisTheir
PronounSheThey
VerbPlaysPlay

The Plural Forms of Words

The word plural means more than one in number. So, the plural form of the word cat is cats, and the plural form of mouse is mice. (Plural is the opposite of singular.)

The term plural does not just apply to nouns (e.g., cats, mice), it also applies to pronouns (e.g., we, us, they, them), adjectives (e.g., these, their), and verbs (e.g., we play, you sing).

Forming the Plurals of Nouns

In most cases, a noun will form its plural by adding s to the singular form. For example:
  • 1 dog > 2 dogs
  • 1 house > 2 houses
  • 1 video > 2 videos
(Warning: You must not insert your own apostrophe before the s when forming a plural. This is a serious grammar mistake.)

The rules for forming the plurals of nouns are varied, and errors do occur. Here are the rules for:

What Are the Plural Pronouns?

The singular personal pronouns are I, you, he, she, and it. The plural personal pronouns are we, you, and they. (NB: The personal pronoun you can be both singular or plural. That's because you can say you to mean one person or several.)

Here are the personal pronouns in a table with their full names (plural pronouns shaded):

PronounName
Ifirst person singular
Yousecond person singular
He / She / Itthird person singular
Wefirst person plural
Yousecond person plural
Theythird person plural

What Is the Plural Form of a Verb?

The plural form of a verb is the form that fits with a plural subject. Look at these examples (plural forms shaded):

PronounNameExample Verb
Past Tense
Example Verb
Present Tense
Example Verb
Future Tense
Ifirst person singularI ateI eatI will eat
Yousecond person singularYou ate You eat You will eat
He / She / Itthird person singularHe ate He eatsHe will eat
Wefirst person pluralWe ateWe eatWe will eat
Yousecond person pluralYou ateYou eatYou will eat
Theythird person pluralThey ateThey eatThey will eat

The English language is quite unusual because the singular and plural forms of verbs in each tense are identical. The only exception is the third-person-singular form in the present tense (shown in red). This is the main reason why English is easy for foreigners to learn. In many other languages, there would be a different spelling in every single box in the table above.

What Are Plural Demonstrative Adjectives?

The demonstrative adjectives are thisthatthese, and those.

The singular ones are this and that. The plural ones are these and those.

This is worth knowing because these and those must be paired with a plural word. In others, you cannot say:
  • These kind of things.
You must say:
  • These kinds of things.

Forming the Plurals of Foreign Words

Words "stolen" from other languages form their plurals in a variety of ways. Examples:
  • stadium > stadia or stadiums
  • (Through common usage, the plural stadiums is acceptable too.)
  • datum > data
  • radius > radii or radiuses
  • (Through common usage, the plural radiuses is acceptable too.)
  • agendum > agenda
Beware

Do Not Use an Apostrophe to Form a Plural

As covered here, lots of nouns form their plurals by adding s, es, or ies. It is a mistake to add your own apostrophe.

So, when forming a plural, do not use an apostrophe before the final s.
  • Using the new cutter, the team can lay 2 patio's in a day.
  • (This should be patios.)
  • As far as I am concerned, they are all hero's.
  • (This should be heroes.)
  • The block has 15 storey's.
  • (This should be
    storeys stories .)

Using an Apostrophe for an Awkward Plural

Using an apostrophe in a plural is the most common error regarding plurals. However, in some rare circumstances (e.g., to show the plural of written figures, letters, words, and some abbreviations), it is permissible to use an apostrophe to a show plural:
  • Alan achieved 2 B's and 3 C's.
  • (The apostrophes are not necessary, but they are acceptable.)
  • Your 2's look like your 7's.
  • (The apostrophes are not necessary, but they are acceptable.)
  • She used too many and's in her writing.
  • (The apostrophe is not necessary, but it is acceptable.)
  • There were 3 COS's at the meeting.
  • (COS - Chief of Staff)
    (The apostrophe is not necessary, but it is acceptable.)
Read more about apostrophes to show awkward plurals.

Warning: Be aware that even though it is acceptable to use an apostrophe to show a plural in these circumstances, there is a high chance that many of your readers won't like it. So, you should avoid it unless you think it is necessary to help your readers. For example:
  • There are two i's in skiing.
  • (It is difficult to argue that the apostrophe doesn't help.)
Top Tip

Singular or Plural?

Criteria is a plural word. It is the plural of criterion.
  • The criteria are non-negotiable.
  • The criteria is non-negotiable.
Although agenda and data are plural words too (from agendum and datum), it is acceptable to treat them like singular words nowadays.
  • Tomorrow's agenda is pinned on the notice board.
  • Tomorrow's agenda are pinned on the notice board.
  • My data was corrupted by the surge.
  • My data were corrupted by the surge.
Both the singular and the plural versions are acceptable. However, be aware that treating data and agenda as plural words can look a little pretentious nowadays.