How to Use a Cardinal Number as an Adjective

When we put a cardinal number in front of a noun, we are using it as an adjective. Take a look at some examples of how to use a cardinal number as an adjective.

Noun-Adjective Agreement

An adjective in Spanish generally agrees with its noun in gender and number. However, when a cardinal number is used as an adjective, it typically doesn't change to match the gender or number of the noun it modifies. Spoiler alert: There are some exceptions to this rule.

Unochanges to unwhen used to describe masculine nouns and unawhen used to describe feminine nouns. Numbers ending in uno, like veintiunoand cuarenta y unoalso undergo these changes.

Cienchanges to cientoin numbers above 100. If the cardinal number being used as an adjective is between 101 and 199, ciento does not change to match the noun. However, ciento must be in agreement with a feminine noun when the cardinal number is above 200.