In English, the verb in a sentence changes depending on if the noun is singular or plural. For example, it would be grammatically wrong to write "We is here", since we is plural but is is the singular form of the verb. We need to keep track of which words are singular and which are plural, but since we learn that when we learn the word, it isn't too difficult.

In Spanish, we also need to keep track of another attribute, called the gender. Spanish has two grammatical genders, which are known as "masculine" and "feminine". While feminine gender is used mostly with females, masculine gender is used broadly. Just like a word can be singular or plural, it can also be masculine or feminine. Sometimes it is obvious which gender a word is, such as the words for man and woman. Other times, it may seem arbitrary. Just learn the gender of each noun you learn, and you won't have too much trouble.

Gender of sexed nouns

Normally, for nouns that express entities with sex (people or animals) there is both a masculine-gender form and a feminine-gender form (example: el profesor (m), la profesora (f)). Normally, the feminine-gender words end with the letter 'a' and the masculine words end with the letter 'o'. If a masculine word ends with a consonant, the feminine adds 'a'. If word ends in 'a' it can be both masculine and feminine (el artista, la artista).

Examples:

Sex is not correctly expressed by the gender alone. If you want to say "I need a female student" you can say Necesito una alumna. However, since gender is required but doesn't convey additional meaning, the sentence would be better understood if you say Necesito una alumna mujer.

In the plural the masculine-gender form indicates there is at least one male, or that sex is unknown. Los niños is the children. To indicate boys you must say los niños varones or los niños hombres (the male children).

See also Formation of the feminine

Gender of non sexed nouns

Many words in Spanish have a fixed arbitrary gender, which is also called gramatical gender. This is true for all things: el pan (bread), la leche (milk). Most animals follow this rule: el camello (camel), la jirafa (giraffe). There are a few words applied to persons that have grammatical gender: el personaje (personage, character), la visita (visitor).

Normally, the feminine-gender words finalize with the letter 'a' and the masculine-gender words end with the letter 'o'.

Examples:

Masculine-gender words ending in o:

Feminine-gender words ending in a:

Here the endings that are typical for feminine nouns.

A mnemonic rule for most feminine-gender endings is the "word" D-ión-Z-A.

There is also a (much less strict) rule for typical masculine-gender endings. The endings can be summarized easily by the word L-O-N-E-R-S:

Since there are many exceptions to some of the rules it is always good to learn the gender along with the noun. Definite articles normally help us to do this.

Some of these exceptions can be memorized in groups. For example, although most nouns that end in "-a" are feminine and therefore take the "la" article, many nouns that end in -ma are exceptions to the rule and are masculine. This is because these words have a Greek origin. For example, el tema, el programa, el fantasma, el clima and el diploma. However, many words ending in -ma have a feminine gender: la cama, la broma, la norma, la rama, la fama, la yema, la estima, la espuma.