1. Gender of Nouns in Spanish
Spanish nouns are either masculine or feminine. The article in front of the noun signifies the noun’s gender.
Singular Plural 
Masculine el/un libro los/unos libros
Femenine la/una mesa las/unas mesas

2. Gender of Nouns in Spanish
If the noun does not have a written article, here are some helpful hints to figure out if the noun is masculine or feminine. The following are helpful guidelines to follow and not standard rules.

3. Gender of Nouns in Spanish
The noun is usually masculine if it:
1. ends in an “o”
example: el ojo
2. ends in a consonant (l, n, r)
example: el papel , el cinturón, el collar
3. ends in “ma” “pa”
example: el programa, el mapa
4. refers to something or someone
masculine
example: el padre (father)

4. Gender of Nouns in Spanish
The noun is usually feminine if it:
1. ends in “a”
example: la silla
2. ends in “ción” “sión”
example: la educación
3. ends in “dad” “tad” “tud”
example: la universidad
4. refers to something or someone
feminine
example: la madre (mother)

5. Definite Articles (Los artículos definidos)
Articles in Spanish
“THE” 
Definite Articles (Los artículos definidos)
* In English, the definite article is the. It is used to refer to a specific noun or group of nouns. Example: the coat, the dogs.
*In Spanish, there are four different definite articles to be used with nouns. The one that is appropriate depends on the gender and number of the noun. Example: el dedo, la oreja, los ojos, las caderas

6. Definite Articles (Los artículos definidos)
Articles in Spanish
“THE” 
Definite Articles (Los artículos definidos)
* Definite articles are frequently used in Spanish classes to show students the gender of new words they are learning. If you know the appropriate article to use, you know the gender of the noun.
* Here are the four articles, organized by gender (masculine or feminine) and number (singular or plural):
Singular Plural
Masculine el libro los libos
Femenine la silla las sillas

7. Indefinite Articles (Los artículos indefinidos)
Articles in Spanish
“A/AN, SOME, A FEW”
Indefinite Articles (Los artículos indefinidos)
* In English, indefinite articles are a, an, some, and a few. They are used to refer to a more general noun or group of nouns. Example: a cookie, some chairs, an apron
* There are four indefinite articles that correspond to the definite articles. The appropriate one depends on the number and gender of the noun. Example: un estómago, una lengua, unos dedos, unas bocas

8. Indefinite Articles (Los artículos indefinidos)
Articles in Spanish
“A/AN, SOME, A FEW”
Indefinite Articles (Los artículos indefinidos)
* The Spanish indefinite articles un and una correspond to the English a and an. The Spanish indefinite articles unos and unas correspond to the English some and a few.
* Here are the four articles, organized by gender (masculine or feminine) and number (singular or plural):
Singular Plural
Masculine un libro unos libros
Feminine una silla unas sillas