- 單數:代表只有一個物體。
- 複數:代表有多個物體,一般是該語言所擁有的最大的數以上的數。
- 雙數:代表有兩個物體。
- 三數:代表有三個物體。目前已知有三數的自然語言,其三數皆僅存於代詞中。[來源請求]
- Beard, R. (1992) Number. In W. Bright (ed.) International Encyclopedia of Linguistics.
- Corbett, G. (2000). Number. Cambridge University Press.
- Greenberg, Joseph H. (1972) Numeral classifiers and substantival number: Problems in the genesis of a linguistic type. Working Papers on Language Universals (Stanford University) 9. 1-39.
- Laycock, Henry. (2005) 'Mass nouns, Count nouns and Non-count nouns' Encyclopedia of Language and Linguistics. Oxford: Elsevier.
- Laycock, Henry. (2006) Words without Objects. Oxford: Clarendon Press.