Semantic vs. grammatical number

All languages are able to specify the quantity of referents. They may do so by lexical means with words such as English a few, some, one, two, five hundred. However, not every language has a grammatical category of number. Grammatical number is expressed by morphological and/or syntactic means. That is, it is indicated by certain grammatical elements, such as through affixes or number words. Grammatical number may be thought of as the indication of semantic number through grammar.

Languages that express quantity only by lexical means lack a grammatical category of number. For instance, in Khmer, neither nouns nor verbs carry any grammatical information concerning number: such information can only be conveyed by lexical items such as khlah 'some', pii-bey 'a few', and so on.[2].

Most languages of the world have formal means to express differences of number. The most widespread distinction, as found in English and many other languages, involves a simple two-way number contrast between singular and plural (car / cars; child / children, etc.). Other more elaborate systems of number are described below.