The importance of gender to Spanish grammar is that as a general rule, adjectives must be in a masculine form when they refer to masculine nouns and in a feminine form when they refer to feminine nouns. The masculine definite article (el or los for "the") is also used with masculine nouns and a feminine article (la or las for "the") is used with feminine nouns. Also, masculine pronouns are used when referring to nouns that are of masculine gender, and feminine pronouns when referring to nouns that are of feminine gender. Neuter pronouns are used to refer to unspecified nouns or nouns whose gender isn't known, as in "¿Qué es eso?" for "What is that?" (eso is neuter).

Adjectives don't always vary according to gender; for many adjectives, the masculine and feminine forms are identical. Neuter adjectives are used infrequently, but where they are used they have the same form as the masculine form and are thus indistinguishable from them.

The division of nouns into masculine and feminine genders is somewhat arbitrary. Nouns that naturally refer to males (such as el hombre, "the man") are typically masculine, and nouns that refer to females (such as la muchacha, "the girl") are feminine. However, the gender of other words is usually unpredictable. Although there are many exceptions, it is common for nouns that end in -o to be masculine and those ending in -a to be feminine.

Some nouns can vary in gender depending on the person to whom they're referring. For example, el atleta is masculine and refers to a male athlete, but la atleta is feminine and refers to a female athlete. There are also a few nouns whose meanings vary depending on the gender. For example, the masculine el papa refers to the pope, while the feminine la papa refers to a potato.

Spanish dictionaries generally list adjectives in their masculine form.

English has no corresponding concept of gender when applied to nouns or adjectives. English pronouns do have gender, however; the personal pronouns "he," "she" and "it" are masculine, feminine and neuter, respectively. Although some objects in English can be referred to by a gendered pronoun (such as using "she" to refer to a nation or a ship), these are cases of personification rather than of grammatical gender.

Term in Spanish: el género

Related terms in Spanish: masculino (masculine), femenino (feminine), neutro (neuter)

Example of Spanish sentences using masculine words: Mi hermano es gordo. Él tiene dos coches. Ellos son rojos. ("My brother is fat. He has two cars. They are red." Note that the pronouns and adjectives referring to masculine nouns are masculine.)

Example Spanish sentences using feminine words: Mi prima es flaca. Ella tiene dos camisas. Ellas son rojas. ("My cousin is skinny. She has two shirts. They are red." Note that the pronouns and adjectives referring to feminine nouns are feminine.)

Example of a Spanish sentence using neuter words: Lo bello es caro. No comprendo esto. ("That which is beautiful is expensive. I do not understand this." Note that the neuter pronoun in the first sentence has the same form as if it were masculine. The noun in the first sentence is neuter because it is made from an adjective and doesn't refer to a specific item. The neuter pronoun is used in the second sentence because it refers to the thought of the first sentence rather than to a specific noun.)

Related Resources:

Gender: An Inherent Characteristic of Spanish Nouns
Just as maleness or femaleness is an inherent characteristic of human beings and most animals, so is gender an inherent characteristic of nouns in Spanish.

Adjectives: Agreement with Nouns
Adjectives must match the nouns they refer to in both number and gender.

Gender Reversal
Certainly, it is possible to tell by looking at many nouns whether they're masculine or feminine. But there are many exceptions to the rules.

Doubly Gendered
Some nouns vary in gender depending on the meaning.

Sometimes Masculine, Sometimes Feminine
Most nouns are clearly masculine or clearly feminine. There are some, however, that Spanish speakers and writers can't seem to agree on.