Number in grammar
- singular, which means a single example, as in "The man sings" or "a blue car" or "It is blue"; and
- plural, which means more than one, as in "They sing", "blue cars" or "They are blue".
Number is usually shown by inflections. In English, the plural of the noun is most usually shown by the addition of '-s', or a variant spelling of this, while the singular is 'unmarked' (not inflected). With verbs, the singular (of the third person of the present tense only) is marked by adding '-s' while the plural is normally unmarked. (As is often the case, the verb 'to be' is an exception - the past tense is also inflected to show number - 'I was' but 'we were'.) This apparent contradiction may be a cause of non-native speakers making errors like using a singular verb with a plural subject, and vice versa. There is also a common problem with 3rd person personal pronouns - see 3rd person problem.
- Other languages have more than two grammatical numbers: both Arabic and classical Greek, for example, have a special form (the dual) to indicate two of something.