El is used before masculine nouns, while la is used before feminine nouns.
Here's a simple breakdown:
* El libro: The book (libro is masculine)
* La mesa: The table (mesa is feminine)
However, there are some cases where the gender of a noun might not be immediately obvious.
Here are some helpful tips:
* Ending: Nouns ending in -o are usually masculine, and nouns ending in -a are usually feminine.
* Context: The context of the sentence can often help determine the gender of a noun.
* Dictionary: If you're unsure, you can always check a dictionary for the gender of a noun.
Remember, "el" and "la" are not directly translated as "he" and "she" in English. They are used to specify a particular noun, similar to the function of "the" in English.