Project Nayuki

Problems with plurals in English


In the English language, almost all nouns have both a singular and a plural form. When composing a phrase, the singular or plural form for each noun must be consciously chosen. This is also the case in languages like French, Russian, and Arabic. But in East Asian languages like Korean and Indonesian, every noun has an ambiguous quantity by default, and explicitly marking it as plural is optional.

On the surface, it seems that always marking plurals makes a language like English more meaningful and less ambiguous. But once we get into the finer details of the language, the simple ideas and rules about plurals break down into a mess of special cases and unresolved ambiguities. Although I will mainly talk about situations where plurals in English are problematic, many of these observations apply to other languages that have plurals (even if pluralization is optional).

List of problems

Unmarked words

Some words are understood as either singular or plural without changing the spelling or pronunciation. For example, one sheep, two sheep; salmon, aircraft, species, means. These words still follow the usual rules of subject-verb agreement, e.g. “One deer is heavy”, “Two deer are heavier”. In languages like Chinese where pluralization is optional, every noun has an unmarked plural by default.

Irregular words

There are a handful of words and suffixes that don’t follow the ubiquitous rule of adding an s (or es) to form the plural. For example: ox → oxen, goose → geese, man → men, tooth → teeth, die → dice, radius → radii, half → halves, child → children, person → people. However, many similar rhyming words don’t follow these exceptions: box ↛ boxen, moose ↛ meese, pan ↛ pen, booth ↛ beeth, tie ↛ tice, bus ↛ bi.

Irregular words increase the effort to memorize vocabulary. For uncommon words, even native speakers might mistakenly use the wrong plural form (e.g. axis ↛ axises, virus ↛ viri). Furthermore, the plural form of uncommon words may shift over time to the regular form (e.g. index → indices/indexes).


Some words are pluralized with ’s because adding just an s looks ambiguous. For example, “I received two A’s in high school”. This usage of ’s is debatable in other cases, e.g. the 1930s vs. the 1930’s, ors vs. or’s, PhDs vs. PhD’s. Some writers incorrectly use ’s on normal words (e.g. “apple’s for sale”), a phenomenon known as greengrocers’ apostrophes.

Singular-only words

Some nouns exist only in the singular form, never the plural form. For example: news, information, happiness, mathematics, linguistics, oxygen, silicon, soccer, tennis, insurance, furniture. Notice that some words end in s, despite being singular.

Plural-only words

Some nouns exist only in the plural form, never the singular form. For example: clothes, pants, scissors, cattle, folks, thanks. Notice that some words don’t end in s. There are far fewer of these words than singular-only nouns.

Noun conjunctions

Most of the time, using and to join two nouns (singular or plural) will form a plural, e.g. “My cat and mouse are quiet”. But sometimes, the and denotes a single entity that has multiple components, such as “Smith and Klein is a law firm”.

With the word or, there are no solid guidelines on whether the combination is singular or plural. For example, “Alice or Bob is the perpetrator”, “This or that are both fine”.

Singular they

The pronoun they is usually understood to refer to a group of people, but it can also refer to one person. This usage of singular they is more general than the phrase he/she, as it includes persons of any gender (including non-binary). Singular they still uses verbs for the plural form (otherwise it sounds awkward), e.g. “they are”, “they were”, “they have”, “they sing”. The analog to himself/herself is themselves, but it is debatable whether that is the singular form or themself is the singular form..

Verb gerunds

A verb in the gerund form behaves like a noun. Some gerunds are uncountable (e.g. “driving is easy”), but some do have plural forms (e.g. “two showings of a movie”). The generally accepted usage of each verb seems to be arbitrary, without clear rules.

Adjectives as nouns

As a special case of plural-only words, adjectives can be used as a plural noun to denote the collection of people with that quality. For example, the rich is understood as the people who are rich. Adjectives used in this way are always plural (e.g. “the homeless are at risk”, not “the homeless is at risk”).

Adjectives describing a nationality can also be used this way, e.g. “the British have something” means “the British people have something”. Many nationalities have a noun form, such as a Dane for a Danish person; these are pluralized in the normal way (e.g. “the Danes are”). Some nationalities use the same word as a noun and adjective, in which case the adjective-to-noun rule cannot be used; the plural noun must be used to talk about the entire group (e.g. “Canadians are”, never “Canadian are”). (There are also subtle rules about how the article the is used or not used in front of a nationality word, but that discussion would make a whole separate article.)

Subject-verb agreement

One of the most basic points of English is that the quantity of the subject can influence the form of the verb. For example, “A dog barks”, “Two dogs bark”. This grammatical rule makes English harder than languages without subject-verb agreement, such as Japanese.

A point that confuses beginners is that subject-verb agreement doesn’t necessarily apply to the noun closest to the verb. For example, “a set of pages” is a singular noun, so it is used in a sentence like “A set of pages is thick, not “A set of pages are thick. This rule gets especially difficult if the noun phrase is long and comprises many words.

In addition to subject-verb agreement, languages like French also require the plurality of an adjective to agree with the noun it describes. For example, une belle personne, des belles personnes.

Non-positive integers

Pluralization is well-defined for the numbers 1, 2, 3, etc. (e.g. one cat, two cats, three cats). It is debatable how to apply plurals to other numbers, but the generally accepted grammar looks like this: zero apples, half an orange, 0.74 banana or bananas, 1.9 pears, negative one dollar, −5 pesos.

Metric unit symbols

In metric (SI), full unit names are pluralized as normal (e.g. one gram, two grams), but unit symbols are never pluralized (e.g. 1 m, 2 m) – this improves the clarity of technical writing that involves quantities. Non-metric measurement systems may or may not allow pluralized abbreviations (e.g. pound as lb/lbs, hour as hr/hrs).


When a plural noun does something, it is unclear whether the group as a whole uses the object(s) or each member of the group uses the object(s). For example:

  • The student took out his book. (One student, one book – this is clear.)

  • The student took out his books. (One student, many books – this is clear.)

  • The students took out their book. (The entire group taking out one book they collectively own, or each student taking out their own book?)

  • The students took out their books. (The entire group collectively having multiple books, or each student having multiple books, or each student having one book?)

The same situation occurs with possessives:

  • The girl’s pencil (okay)

  • The girl’s pencils (okay)

  • The girls’ pencil (ambiguous)

  • The girls’ pencils (ambiguous)

Indifference / excess detail

Some phrases have the same meaning whether a noun is plural or not. For example, “Learning a language is hard” and “Learning languages is hard” are both generally understood to mean the same thing. This is because if learning one language is hard, then learning multiple languages is also hard.

Sometimes, one form of a noun is customary but the other form sounds weird or hyper-specific. For example, “he ate carrots for dinner” (normal phrasing) vs. “he ate a carrot for dinner” (exactly one whole carrot, rare to say it this way) vs. “he ate pieces of carrot(s)” (carrots are usually cut up in cooking, so this describes the default situation more explicitly). For example, “she had pizza for lunch” (normal phrasing) vs. “she had a pizza for lunch” (one entire pizza, regardless of size) vs. “she had a slice / some slices of pizza” (unusually specific about taking slices from a larger whole pizza).

Classes of objects

In normal English, we speak of a class of objects with a plural. For example, “the set of all students”, or “students are lazy”. We say that “Carol is a member of (the collection of) students”, but “Dave is a student”.

In object-oriented computer programming, we specify a set of behaviors for a class of objects. For example, class Student { ... } contains code that applies to each and every individual student (such as having a name), but may also contain code that applies to the entire universe of students as a whole (such as the count of everyone). To instantiate a student, we write Student s = new Student("John");. The code would be weird if the class name was plural, like Students s = new Students("John");. Thus we always name a class in singular form.

A similar problem occurs when designing database tables. Suppose a table has one row per employee. Since the table is a collection of rows, it is natural to name the table as employees. Now suppose we perform a query where we select an employee by age. The code in SQL would be like SELECT * FROM employees WHERE employees.age=(...). Even though the code executes correctly, the expression employees.age looks misleading to a human. This is because each employee (row) has an age field, but there is no such thing as an age for the entire collection of employees (i.e. for the table as a whole). Therefore, it is problematic whether we name the table in singular or in plural.

French: Obscured gender

In French, singular nouns have articles that clearly mark the word’s gender (e.g. un bureau, une chaise), but plural nouns have the same article regardless of gender (e.g. des tables). The same applies to le/la/les and du / de la / des.


The English language is what it is, and I am not proposing to change how it functions. What I wanted to illustrate is that for a simple idea like marking every word as singular or plural, which appears to be beneficial at a glance, leads to a plethora of subtle consequences like irregular words, words that have either no singular or plural counterpart, ambiguities that still remain, and much more.

When a European language speaker hears the fact that some language (e.g. Vietnamese) has optional plurals, a common knee-jerk reaction goes something like “It must be so confusing if they can’t tell plurals in the language!”. Hopefully, this article sheds some light on the counterpoint that having plurals in a language can be just as confusing. It can be understood that a language without mandatory plurals can be just as viable in the real world as a language with mandatory plurals. Finally, I hope this discussion inspires your curiosity to explore and learn different languages – especially ones that challenge some core paradigms in the languages that you already know.

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