Editing Grammatical number (section)

==Overview==
Most languages of the world have formal means to express differences of number. One widespread distinction, found in English and many other languages, involves a simple two-way contrast between singular and plural number (''car''/''cars'', ''child''/''children'', etc.). Discussion of other more elaborate systems of number appears below. 

Grammatical number is a morphological category characterized by the expression of [[quantity]] through inflection or agreement. As an example, consider the English sentences below:
{{block indent |left=1.5 |text={{plainlist}}
* ''That apple on the table is fresh.''
* ''Those two apples on the table are fresh.''
{{endplainlist}}}}

The quantity of apples is marked on the noun—"apple" '''singular number''' (one item) vs. "apples" '''plural number''' (more than one item)—on the demonstrative, ''that/those'', and on the verb, ''is/are''. In the second sentence, all this information is [[Redundancy (linguistics)|redundant]], since quantity is already indicated by the numeral ''two''.

A language has grammatical number when its noun forms are subdivided into [[morphology (linguistics)|morphological classes]] according to the quantity they express, such that:
#Every [[noun]] form belongs to a number class (they are partitioned into disjoint classes by number).
#Noun [[modifier (linguistics)|modifiers]] (such as adjectives) and [[verb]]s may also have different forms for each number subclass and [[inflection|inflect]] to match the number of the nouns they modify or agree with (number is an [[agreement (linguistics)|agreement category]]).

This is partly true for English: every noun and pronoun form is singular or plural (a few, such as "[[Fish#"Fish" or "fishes"|fish]]", "[[Cannon#Etymology and terminology|cannon]]" and "[[you]]", can be either, according to context). Some modifiers of nouns—namely the [[demonstrative]] determiners—and finite [[verb]]s inflect to agree with the number of the noun forms they modify or have as subject: ''this car'' and ''these cars'' are correct, while *''this cars'' and *''these car'' are incorrect. However, adjectives do not inflect for and many verb forms do not distinguish between singular and plural ("She/They went", "She/They can go", "She/They had gone", "She/They will go"). 

Many languages distinguish between [[Count noun|count nouns]] and [[Mass noun|mass nouns]]. Only count nouns can be freely used in the singular and in the plural. Mass nouns, like "milk", "gold", and "furniture", are normally invariant.<ref>{{cite journal |last=Nicolas |first=David |date=2008 |title=Mass Nouns and Plural Logic |url=http://d.a.nicolas.free.fr/pdf/Nicolas-Mass-nouns-and-plural-logic.pdf |journal=Linguistics and Philosophy |volume=31 |issue=2 |pages=211–244 [213] |doi=10.1007/s10988-008-9033-2 |s2cid=13755223 |access-date=2024-01-23 |url-status=live |archive-url=https://web.archive.org/web/20220419230012/http://d.a.nicolas.free.fr/pdf/Nicolas-Mass-nouns-and-plural-logic.pdf |archive-date=2022-04-19 }}</ref> (In some cases, a normally mass noun '''''X''''' may be used as a count noun to collect several distinct kinds of '''''X''''' into an enumerable group; for example, a cheesemaker might speak of goat, sheep, and cow milk as ''milks''.) 

Not all languages have number as a grammatical category. In those that do not, quantity must be expressed either directly, with [[Numeral (linguistics)|numerals]], or indirectly, through optional [[Quantifier (linguistics)|quantifiers]]. However, many of these languages compensate{{clarify|date=February 2015}} for the lack of grammatical number with an extensive system of [[measure word]]s.

[[Joseph Greenberg]] has proposed a number category hierarchy as a [[Greenberg's linguistic universals|linguistic universal]]: "No language has a trial number unless it has a dual. No language has a dual unless it has a plural."<ref>{{cite book |last=Greenberg |first=Joseph H. |author-link=Joseph Greenberg |editor-last=Greenberg |editor-first=Joseph H. |editor-link=Joseph Greenberg |year=1966 |orig-year=1963 |title=Universals of Language |chapter=Some Universals of Grammar with Particular Reference to the Order of Meaningful Elements |edition=2nd |location=Cambridge, MA |publisher=M.I.T Press |pages=73–113 [94] }}</ref> This hierarchy does not account for the paucal.<ref>{{cite book |last=Corbett |first=Greville G. |author-link=Greville G Corbett |year=2004 |orig-year=2000 |title=Number |series=Cambridge Textbooks in Linguistics |location=Cambridge |publisher=Cambridge University Press |page=39 |isbn=0-511-01591-7 }}</ref>