tercer

Tercer is the masculine singular ordinal adjective in Spanish that means “third.” It is derived from the word tercero and is used to indicate position in a sequence. The feminine form is tercera, and plural forms are terceros (masculine) and terceras (feminine).

Usage and forms

When placed directly before a masculine singular noun, many speakers use tercER to ease pronunciation, producing forms such as tercer día or tercer año. If the ordinal follows the noun or is used as a noun itself, the form tercero is common, as in día tercero or los terceros in some contexts. The same agreement rules apply in the feminine: before a feminine singular noun, you would use tercera (e.g., tercera etapa); as a substantive, the form puede trabajar con tercera, depending on context.

Common patterns

Tercer tends to be favored before masculine singular nouns that begin with a stressed a- or ha- for ease of pronunciation, though both tercERo and tercero can occur in actual usage depending on emphasis and regional preference. The feminine counterpart follows the same pre-nominal behavior with tercera, and the plural forms son terceros and terceras to agree with the noun.

Notes

Tercer appears in everyday language as well as in formal writing. It is also used in fixed expressions such as terceros mundos or third-world contexts, and in academic or legal language where ordinal numerals appear in pre-nominal position. Etymologically, it shares roots with the Latin tertius, and its English counterpart is third.

See also: ordinal numbers in Spanish, grammar of adjectives, Spanish pronunciation.