Veintiún

Veintiún is the Spanish cardinal number that represents the quantity twenty-one. It is formed from the combination of veinte and uno, with elision of the final o of uno and a written accent to indicate the correct stress: veintiún.

In standard usage, veintiún is used before masculine singular nouns. For example, veintiún días, veintiún hombres. When the following noun is feminine and singular, the form veintiuna is used, as in veintiuna amigas or veintiuna páginas. The numeral does not change to reflect plural nouns; the noun after it carries the plural form if needed (for example, veintiún libros, veintiuna personas).

The form veintiuno is used in other contexts, such as when the number stands alone or when no masculine singular noun follows, for instance in counting or as a pronoun: veintiuno es mi edad (twenty-one is my age) or simply veintiuno.

Orthography and style guidance from Dาจes particulares of Spanish grammar emphasize the contracted veintiún before masculine singular nouns and veintiuna before feminine singular nouns. The form veintiuno remains common when the numeral is used independently or before certain non-noun phrases.

Etymologically, veintiún reflects a regular evolution from veinte + uno, with the accent added to preserve natural stress and to distinguish it from the feminine form. This distinction between veintiún and veintiuna is a notable feature of Spanish numerals used before nouns.