What is the diffence in el, la, los,? I mean how do I use them in defining a word like libros?
I have a homework assignment in my Spanish class and it is with definite articles and indefinite articles. But they include el, la, los, las, for definite and un, una, unos, unas for indefinite; which i don't really know what im doing exactly with them because they want me to use them with other words like casa and libros. I'm just really confused and I need help with this!
5 Answers
So, Aaron, how's it going?
Just a note on the difference between definite and indefinite:
A general thing is a thing. In English, this is a, or some. Indefinite, non-specific:
I love bees. There are some bees in my garden. A bee is a wonderful insect.
Definite means it is specific, defined, standing out from the swarm:
The bees that stung my dog were all over his back! I washed off the bees as best I could. The, the, the. Specific bees.
P.S. That really happened. Except they were wasps. The dog (definite article) was frantic, running like he had the devil after him! I guess a dog (indefinite) can't save itself! I'm glad I was there with the hose.
In Spanish el, la, los las, are used with nouns. el and los are used in conjunction with masculine words, la and las are used with femenine words. Masculine words typically end in o or for plural, os. Feminine words typically and in a or for plural, as. In the case of libros, it ends in os maing it masculine and is also plural because of the os so Los libros would be correct. El libro would be used for the singular version of the word.
There are some general rules for gender determination like most words ending in a are feminine and many ending in o are masculine, but there are many exceptions and sometimes even feminine words don't take la under certain conditions.
There are some other word endings like ción that are almost always feminine, and a few more patterns of word endings, but again, most have exceptions.
I know you don't want to hear it, but the best way to be sure of a noun's gender is to look it up in the dictionary when you learn the word.
The definite articles match the noun that they precede in number. los libros
Indefinite articles follow the similar rules with a few more thrown in to increase your fun, like apocopation.
Try taking lesson 1:3 on this site. Paralee does an excellent job of explaining it. We are not really supposed to help with homework.
But I guess I can help you understand the concept. Basically, think of el, los, la and las as the English word "the". Un, unos, una and unas take the place of the English words "a" and "an".
This was probably explained by your teacher, but I know sometimes we don't catch things the first time around. So I hope this helps. Now...Do your homework! 
Hi Aaron. Welcome to the forum. 
Here’s a link to an article in the Reference section on how to use definite and indefinite articles.
