Nouns: gender and number

What it is

Every Spanish noun is masculine or feminine, even things and ideas: el libro (the book) is masculine, la mesa (the table) is feminine. For objects, gender is just a grammar label, but it decides the form of the words around the noun: the article (el, la, un, una) and, later, the adjectives. Nouns also have number: singular (un libro) or plural (dos libros).

The habit that saves the most mistakes: learn every noun together with its article. Learn la casa, not just casa.

How to form it

Gender. The ending is a strong clue, but some very common words break the pattern:

People. With people, gender usually follows the person:

• -o → -a: el amigo, la amiga; el hermano, la hermana.
• Consonant + -a: el profesor, la profesora; el doctor, la doctora.
• One form, two articles: el / la estudiante, el / la artista, el / la turista, el / la joven.
• Different words: el padre / la madre, el hombre / la mujer.

Number.

The stressed syllable never moves, so the written accent can disappear or appear: canción → canciones, alemán → alemanes, but examen → exámenes, joven → jóvenes.

When to use it

You need gender and number every time you use a noun, because the article must match it: la canción, las canciones; el problema, los problemas. Two more things to know from the start:

• Mixed groups take the masculine plural: mis padres (my father and mother), los hermanos (brothers, or brothers and sisters), los hijos (sons and daughters).
• Days of the week are masculine, and the ones in -s don't change: el lunes, los lunes.

• El problema es el idioma, no el sistema.The problem is the language, not the system.-ma: masculine
• —¿De dónde es la foto? —De Valparaíso.—Where is the photo from? —Valparaíso.la foto = la fotografía
• Los lápices son para la clase.The pencils are for the class.z → c
• Somos estudiantes de Bolivia.We are students from Bolivia.el / la estudiante
• Mis padres son de Puebla.My parents are from Puebla.mixed group
• Los exámenes son en diciembre.The exams are in December.examen → exámenes

Contrasts and traps

• -a is not always feminine, -o not always masculine: el día, el mapa, el idioma; la mano, la foto. Foto and moto are short for la fotografía and la motocicleta.
• No estudianta: nouns in -ante and -ista change only the article: la estudiante, la artista.
• Unstressed or stressed -s? el lunes → los lunes, la crisis → las crisis, but el mes → los meses, el autobús → los autobuses.
• La radio is the medium everywhere; for the set itself, el radio is usual in Mexico, Central America and the Caribbean.
• El agua is feminine: it takes el only because it starts with a stressed a (more in the articles topic).

If you also speak Portuguese

Most genders match (o problema, a mão, o dia), but some switch: el viaje, el mensaje, el árbol, el color, el dolor are masculine; la leche, la sal, la nariz, la sangre are feminine. Plurals differ too: papeles (not papéis), veces (not vezes), jóvenes (not jovens).