In linguistics, number is a grammatical category that specifies the quantity of a noun or affects the form of a verb or other part of speech depending on the quantity of the noun to which it refers. Grammatical number is distinct from the use of numerals to specify the exact quantify of a noun; number is usually vague. The most common scheme is singular (one thing) contrasted with plural (many things). Other possibilities include:

• dual number, for two instances of the noun;
• trial number, for three instances of the noun;
• paucal number, for a few (as opposed to many) instances of the noun;
• nullar number, for zero instances of the noun; and
• collective number, for the whole class of the noun (e.g., mankind).

Languages that distinguish grammatical number commonly do so by inflection. Verbs and other parts of speech may be inflected to agree with the noun. English does this in a limited way: "he sleeps" but "they sleep"; "this chair" but "these chairs". Mandarin Chinese, which normally does not distinguish number in nouns, distinguishes it in pronouns. It even has two separate plurals for we, the exclusive wǒmen (我们) and the inclusive zánmen (咱们).

English examples

English is typical of languages that have only singular and plural number. English does not distinguish among dual, trial, or paucal number. The plural form of a word is usually created by adding the suffix -s. Pronouns are irregular precisely because they are so common, such as the singular I and the plural we.

See English plural for detail.

Other languages

Slovene is more complicated:

• babarija (old wives tale) (singular), babariji (two old wives tales) (dual), babarije (three old wives tales), baberij (five or more old wives tales)
• hiša (house) (singular), hiši (two houses) (dual), tri hiše (three houses) (plural), šest hiš (six houses) (plural)
• miš (mouse) (singular), miši (two or three mice) (dual := plural)
• jaz (I) (singular), midva/midve (we) (dual + [Masculine/Feminine gender]), mi/me (we) (plural [Ma/Fe gender])
• vrata (one door) (singular), dvoje vrat (two doors) (dual), tri vrata (three doors) (plural), [plural noun with different or same form]
• babine (afterbirth period) (archaic meaning) (singular), babini (two afterbirth periods) (dual), babine (three afterbirth periods), [plural noun with different or same form]
• človeštvo (mankind) (singular), človeštvi (two mankind) (dual), človeštva (three mankind), [collective noun with different form]
  • When a number reaches one hundred and one(two) (or several hundred or thousand), singular and dual are used again. (ena knjiga (one book) (singular),dve knjigi (two books) (dual), pet knjig (five books) (plural), sto ena knjiga (101 books) sto dve knjigi(102 books))
  • These and similar examples are very often used incorrectly, even in published or electronic dictionaries.

In Hebrew, most nouns have only singular and plural forms, such as sefer - sfarim ("book - books"), but some have singular, dual, and plural forms, such as yom - yomaim - yamim ("day - two days - days"). Some words occur so often in pairs that what used to be the dual form is now the general plural, such as ayin - eynayim ("eye - eyes"). Adjectives, verbs, and pronouns have only singular and plural, with the plural forms of these being used with dual nouns.

Written French declines nouns for number (singular or plural). In terms of pronunciation, however, the majority of nouns (and adjectives) are not actually declined for number. This is because the -s suffix, which marks plural nouns and adjectives, is not generally pronounced (but see liaison for an exception), and thus does not really show anything; the plural article or determiner is the real indicator of plurality. However, plural nouns still exist in spoken French because some irregular nouns form plurals in a way that is pronounced differently: for example, cheval ("horse") is pronounced , while chevaux ("horses") is pronounced [ʃəvo]. Similarly, some irregular adjectives do decline for number in spoken French.

Inverse number

The languages of the Kiowa-Tanoan family have three numbers - singular, dual, and plural - and exhibit an unusual system, called inverse number, of marking number. In this scheme, every countable noun has what might be called its "inherent" or "expected" numbers, and is unmarked for these numbers. When a noun appears in an inverse ("unexpected") number, it is inflected to mark this. For example, in Jemez , where nouns take the ending -sh to denote an inverse number, there are four noun classes, as follows:

As can be seen, class-I nouns are inherently singular, class-II nouns are inherently plural, class-III nouns are inherently singular or plural. Class-IV nouns cannot be counted and are never marked with -sh.

(Sprott, 1992, p. 53)

Effect of number verbs and other parts of speech

Not only nouns can be declined by number. In many languages, adjectives are declined according to the number of the noun they modify. For example, in French, one may say un arbre vert (a green tree), and des arbres verts ([some] green trees). The word vert (green), in the singular, becomes verts for the plural (unlike English green, which remains green).

In many languages, verbs are conjugated by number as well. Using French as an example again, one says je vois (I see), but nous voyons (we see). The verb voir (to see) in the first person changes from vois in singular, to voyons in plural. In English this occurs in the third person (she runs, they run) but not first or second.

Normally verbs agree with their subject noun in number. But in Ancient Greek and Sanskrit neuter plurals took a singular verb. In English, or at least British English, singular nouns collectively referring to people may take plural verbs, as the committee are meeting; use of this varies by dialect and level of formality.

Other qualifiers may also agree in number. The English article the does not, the demonstratives this, that do, becoming these, those, and the article a, an is omitted or changed to some in the plural. In French and German, the definite articles have gender distinctions in the singular but not the plural. In Portuguese, the indefinite article um, uma has plural forms uns, umas.

See also

• collective noun
• grammar
• mass noun
• measure word

Bibliography

• Merrifield, William. (1959). Classification of Kiowa nouns. International Journal of American Linguistics, 25, 269-271.
• Mithun, Marianne. (1999). The languages of native North America (pp. 81-82, 444-445). Cambridge: Cambridge University Press.
• Sprott, Robert. (1992). Jemez syntax. (Doctoral dissertation, University of Chicago).
• Wonderly, William; Gibson, Lornia; & Kirk, Paul. (1954). Number in Kiowa: Nouns, demonstratives, and adjectives. International Journal of American Linguistics, 20, 1-7.