number in English

Every count noun in English is singular or plural and cannot be neither. The regular exponent is a suffix with three pronunciations conditioned by the final sound of the stem, and a small set of nouns forms the plural by vowel change or by an older ending instead, while a few have identical singular and plural forms and are read from what agrees with them. Two values is the whole inventory: there is no dual, no trial and no separate greater plural, and a language that grades number more finely draws contrasts this one has no forms for.

What is notable is how little of the clause the contrast reaches. The determiner does not vary, except for the two demonstratives, which are the only determiners in the language with a plural form. The adjective never varies. The verb varies in exactly one cell, the third person singular of the present, where the presence of the ending signals a singular subject and its absence signals everything else, and the verb be varies in two more. Outside those cells the finite verb tells a reader nothing about the number of its subject. So the marking is obligatory on the noun and almost invisible everywhere else, which is a very different distribution from a language that copies number onto every determiner, every adjective and every finite verb.

The obligatoriness is recorded as obligatory rather than pervasive because the contrast applies where it applies and not universally. A mass noun takes no number at all and is not thereby unmarked: the question does not arise for it, and forcing a plural on one either coerces a count reading or is ungrammatical. Number is also the reason two dimensions in this graph list the same word class twice, since the noun phrase and the verb both register it, and the agreement in the verb is a copy of a value that originates on the noun.