El libro/un libro [the book/a book] is masculine because it ends in o and uses the articles el and un. It has nothing to do with whether books are read or written by men.

La policía [the police force] is a feminine word but that doesn't mean that it is run or staffed by women, or is a feminine profession.

However, words that refer directly to people (or animals) do reflect the gender of the actual person being described. For example, the word for “son” is hijo and the word for "daughter" is hija. The same occurs for the words for "mother, father, sister, brother, aunt, uncle, wife," etc.

Gender is simply a categorization which determines the form of adjectives and articles which modify nouns. We could think of the classification as simply:

Category 1 (masculine)

Category 2 (Feminine)

There are rules for most gender determinations.

Category 1 (masculine)

Category 2 (Feminine)

Word-endings that identify masculine words include: Most words ending with " -o" All words ending with " -aje, -or, -ambre, -án, a stressed (accented) vowel such as í or ú" Most words ending with "r, l, s, n" Foreign words, for example: Greek origen: el planeta el cometa el sistema solar el programa English origen: el hardware el software el jonrón (homerun) Examples: el cuaderno, el equipaje, el amor, el enjambre, el marzapán, el rubí, el champú, el valor, el cañon, el paraguas

Word-endings that identify feminine words include: most words ending with "-a" all words ending with "-ción, -sión" words ending with "-tad, -dad, -tud words ending with "-umbre, -cia"   Examples: la pizarra, la lección, la libertad, la verdad, la virtud, la muchedumbre, la presencia

• Words ending in "e" have to be learned with their article:

  • el pupitre, la clase, el coche, la serpiente