Plural number

In linguistics, grammatical number is a grammatical category of nouns, pronouns, and adjective and verb agreement that expresses count distinctions (such as "one", "two", or "three or more"). In many languages, including English, the number categories are singular and plural. Some languages also have a dual, trial, quadral and paucal number or other arrangements.

The count distinctions typically, but not always, correspond to the actual count of the referents of the marked noun or pronoun.

The word "number" is also used in linguistics to describe the distinction between certain grammatical aspects that indicate the number of times an event occurs, such as the semelfactive aspect, the iterative aspect, etc. For that use of the term, see "Grammatical aspect".

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 number contrast between singular and plural (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:

The number 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 redundant, since quantity is already indicated by the numeral "two".

A language has grammatical number when its nouns are subdivided into morphological classes according to the quantity they express, such that:

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