One day someone in my class asked the very good question, "How do you know when to use a definite article in Spanish?" I gave the very bad answer, "Uh... well..." (The real answer for me is "when it sounds right." Imagine trying to answer the same question about English.)
I then started asking other Spanish speakers whether they had ever heard any rules, and by luck I ran across a linguist who had just written a paper on the topic. She gave me the following explanation, which seems to cover most of the bases:
If you would use an article in English, you use one in Spanish. If you would not use an article in English, you don't use one in Spanish. :
1. The definite article is used in Spanish with gustar:
Philosophy is difficult butLa filosofía es difícil
Roberto Castillo studies archaeology and Roberto estudia arqueología.
(Notice that this rule also explains rule #1. In "Me gustan las manzanas," you're once again talking about all apples, apples in general.)
3. The definite article is used in Spanish with some country names, although this rule is fading from the language and varies regionally. Generally, you'll need to pay close attention (or ask someone) when you learn a new country name. Of the Spanish-speaking countries, Argentina and Perú often have the article.
En el departamento de español, hay muchos instructores de(l) Perú.
¿Está la Srta. Gómez?
[But note the following: "Buenos días, Dr. Iglesias."]
I have biology on Wednesdays but Tengo clase de biología los miércoles
Let's watch Destinos at six but Veamos Destinos a las seis.
This is by no means a complete list of all rules about articles! However, it does cover the most basic, frequent situations you'll run across, and keeping these things in mind will give you a good start. Naturally, the best way to learn this is to pay close attention to what you hear and read, and try to formulate your own system of rules. If you do this, eventually you'll be able to discard the rules in favor of your own sense of what "sounds right."
Copyright Ann Wildermuth and Rosamaría Graziani (University of Texas at Austin, 1996, 2000) To request permission to use this page or any portion of its contents, contact the authors by e-mail.