IT used to be that a picture was worth a thousand words. That was before digital manipulation. Anyway, for understanding, I have always preferred a good example to a picture. I especially prefer a good example to a detailed grammatical explanation.
See what you can make of the following examples:
–¡Qué bella estás esta noche! (How beautiful you look tonight!)
–¡Qué bella eres, mi amor! (How beautiful you are, my love!)
–Estoy muy alegre hoy. (I am feeling happy today.)
–Soy alegre por naturaleza. (I am happy by nature.)
–El día está caliente. (It is a hot day.)
–Quepos es muy caliente. (Quepos is very hot.)
–¿Qúe pasa? El agua está sucia. (What’s going on? The water is [has turned] dirty.)
–El agua de este río es sucia. (The water from this river is dirty.)
–Usted está joven. (You look young.)
–Usted es demasiado joven para morir. (You are too young to die.)
–La maleta está demasiado pesada. (The suitcase is too heavy [because of its contents].)
–¡Qúe pesada es esta silla! (How heavy this chair is!)
–Melina es muy pesada. (Melina is bothersome.)
–No estoy lista. (I am not ready.)
–No soy bastante lista para ti. (I am not clever enough for you.)
–El paciente está mejor. (The patient is better.)
–¿Cuál es mejor? La cerveza o el vino? (Which isbetter, the beer or the wine?)
–¿Cómo está usted? (How are you [feeling]?)
–¿Cómo es usted? (What are you like?)
–¿Dónde está usted? (Where are you?)
–¿De dónde es usted? (Where are you from?)
IF you deduce from these examples that estar expresses a temporary, changeable state and ser expresses a permanent, intrinsic state, you’re doing just fine. You can also see that, in some cases, you have to be very careful about which of these two verbs you use.
Now, take a look at these examples:
–Yo lo sabía. Estás aburrido. (I knew it. You are bored.)
–¿Sabes qúe? Eres aburrido. (You know what? You are boring.)
–Mis padres están cansados. (My parents are tired.)
–Este trabajo es muy cansado. (This job is very tiring.)
–No estoy entendido. (I am not understood.)
–Soy muy entendido. (I am very understanding [intelligent].)
–No estoy nada divertida. (I am not entertained [having a good time] at all.)
–Mario siempre ha sido muy divertido. (Mario has always been very entertaining.)
HERE you can see that, in a few cases, estar or ser make the same kind of discriminations that our past participles (-ed words) and present participles (-ing words) make. Note, in fact, that here, English is also expressing temporary versus permanent.
In other cases, verb choice creates another kind of distinction:
–La Profesora León está preparada para todo. (Professor León is prepared for everything.)
–La Profesora León es bien preparada. (Professor León is well educated.)
–Estamos enamorados. (We are in love.)
–Somos enamorados. (We [are the kind of people who] fall in love easily.)
SOMETIMES, it doesn’t seem to make any difference, or it’s all how you interpret it:
–Estamos casados. (We are married.)
–Somos casados. (We are married.)
HOLD on. If you’re congratulating yourself because you always thought the ser/estar conundrum was difficult but now you realize how simple it really is, forget it.
Here’s the thing: It’s not that people decide to create a language by making up some rules, then building words and sentences around them. Languages just develop on their own; then, people called grammarians come along and try to wrench rules out of them. It is always being said, for example, that estar indicates location, and then somebody comes along and asks you, “¿Dónde es la fiesta?” (Where is the party?).
In fact, if you want a solid rule about any language, here it is: Don’t count on anything. Wait! On second thought, don’t even count on not counting on anything, because you can, in fact, count on always using estar with any progressive tense:
–Estamos estudiando. (We are studying.)
–Los doctores estaban tomando café. (The doctors were drinking coffee.)
–¿Has estado viajando mucho? (Have you been traveling a lot?)
HOWEVER, there ends any certainty. Take a look at these:
–Carlos está muerto. (Carlos is dead.) (How temporary is that?)
–Es posible. (It is possible.) (How permanent is that?)
–Estoy segura. (I am sure.) (How temporary is that?
Actually, “Soy segura” would mean “I am safe.”)
BY the way, if you look all this up in Spanish grammar books, you are likely to find a lot of complicated explanations that will have you ritualistically burning the books in your backyard, and which, when it comes right down to it, don’t make a whole lot of sense. Take this existentialist gem, for example, drawn from a book I otherwise admire: “Estar, from the Latin stare (to stand), indicates… states of being and nonbeing, regardless of permanence.”
In other words, stay away from the grammar books on this one.
SO, what does all this uncertainty mean for you as a non-native speaker? It means that you try, as best you can, to follow the rule that ser expresses the permanent and intrinsic, and estar expresses the temporary and changeable.
Will you make mistakes? Yes, lots of them. Will the native speakers around you follow the same rule? Sometimes yes and sometimes no, and sometimes they’ll simply be able to be more subtle in Spanish than you are – that is, more able to interpret which verb expresses more clearly what they mean.
Don’t let it get you down. That’s language for you.