Masculine nouns ending in -a: why it’s el día and el problema

The ending -a usually points to feminine, and the RAE gives that as the general rule. The exceptions that matter most are a large family of nouns ending in -ma, and a handful of individual words like día and mapa. Adjectives and other words agree in the masculine: el problema difícil, este mapa, un día largo.

This is a different situation from el agua. There the noun is feminine and el is a formal variant of the feminine article; here the noun is masculine and el is the ordinary masculine article. See feminine nouns that take “el”.

Many common masculine nouns ending in -ma come from Greek, directly or through other languages. The RAE lists examples such as clima and esquema. That makes -ma a useful warning sign, not a rule: it tells you a noun is likely masculine, and the dictionary has the final word.

The DLE lists a further sense of tema (an obsession, una idea fija) that it says is also used in the feminine. The main senses are masculine, and el tema is the form to learn.

Outside the -ma family there is no pattern to lean on. These are simply words to learn.

• Not every -ma noun is masculine. La forma is feminine. So are alma and arma, which say el alma and el arma for a different reason (the stressed-/a/ rule, covered in the guide).
• Most -a nouns are still feminine. La casa, la mesa, la semana, la cama. Treat the masculine ones as exceptions you collect, not the default.
• Check words that look unusual. A few nouns have senses in both genders or vary by meaning, so this page only lists nouns whose main sense is clearly masculine in the DLE. Players of ELLA see which ones trip people up most on the hardest nouns page.

Checked against these RAE pages on 7 October 2026. The gender of every noun above was read in its DLE entry.

• Diccionario de la lengua española (DLE) — gender and origin of each noun
• Nueva gramática básica — 2.4.1, Género y terminación
• Diccionario panhispánico de dudas — “el” (alma, arma)