The plural form in Spanish is usually achieved by adding an ‘s’ or ‘es’ at the end of the noun/adjective.

es.   casa : casas;  

malo : malos;

español – españoles;

verdad : verdades;  

cariñoso : cariñosos.

If a noun has an accent on the final syllable, then add ‘es’ and drop the accent.

es:   cajón – cajones;

reunión : reuniones.

With nouns that end with a -z, add ‘es’ and turn the -z into -c.

es:    luz : luces;

andaluz : andaluces.

Foreign words form the plural by adding an ‘s’, unless they end in -s; in that case, they just follow the general rule.

es:   iceberg : icebergs;

record : records;

pass : passes.

Definite and indefinite articles:

el : los

la : las

un : unos

una : unas

If a group of more tan one element contains both masculine and femenine nouns, the masculine plural form is used.

es:   1 gato+2 gatas :tres gatos

Compunds nouns, which are nouns that are composed of two words, usually end with an -s in the singular form as well as in the plural. To make it plural, just change the article.

es:   el pintalabios : los pintalabios;

el abrebotellas : los abrebotellas