Es una persona nerviosa (She's a nervous person) — hoy está nerviosa por el examen (today she's nervous about the exam) — el vaso está roto (the glass is broken). Same idea, "to be," three different jobs for the adjective.

The basic ser/estar split already covers the core idea: ser for identity and defining traits, estar for location and state. With adjectives specifically, it helps to split "state" one step further — a state can be a current condition (está nervioso, nervous right now) or a result of something that changed (está roto, broken because it broke). Both use estar, but recognizing the "result" case makes a lot of everyday adjectives click into place.

Quick shortcut: is the adjective describing what kind of thing/person this is → ser. Is it describing a condition right now, whether temporary or the outcome of a change → estar.

Three lenses, one verb choice

Lens Verb Example
Defining characteristic ser Mi abuelo es nervioso. (My grandfather is a nervous person — it's how he is.)
Current state estar Mi abuelo está nervioso. (My grandfather is nervous right now — before his flight, say.)
Result of a change estar La puerta está abierta. (The door is open — someone opened it.)

The first two are the A1 contrast. The third is the same estar, just triggered by a different kind of situation: something happened, and the adjective names the state that's left over.

Estar + past participle: naming the result of a change

Many Spanish past participles work as adjectives after estar, and they describe exactly this: not the action, but the state it left behind.

  • romper → roto: El vaso está roto. (The glass is broken.)
  • abrir → abierto: La tienda está abierta. (The store is open.)
  • cerrar → cerrado: El banco está cerrado. (The bank is closed.)
  • cansar → cansado: Estoy cansado. (I'm tired — worn out by something.)
  • aburrir → aburrido: Estoy aburrido. (I'm bored — something made me feel this way.)
  • perder → perdido: Estamos perdidos. (We're lost.)

Notice the participle agrees in gender and number like any adjective (roto/rota/rotos/rotas), not like the invariable participle in a compound tense such as he roto (I have broken). Está roto describes the glass now; it doesn't say who broke it or when — that's what a full sentence with romper in a past tense would add (Se rompió ayer, It broke yesterday).

The same adjective, sharper now: characteristic vs result

Some adjectives that seem to be about personality are, with estar, actually about a state triggered by something specific — not just "temporary" in a vague sense, but a state with a cause:

Adjective With ser (characteristic) With estar (state / result)
nervioso Es una persona nerviosa. (He's a nervous person, generally.) Está nervioso por el examen. (He's nervous because of the exam.)
contento — (rarely used with ser this way) Está contenta con su trabajo. (She's happy with her job.)
frío El agua del mar es fría en invierno. (Sea water is cold in winter — a general trait of it then.) El café está frío. (The coffee is cold — it cooled down.)
limpio Es una casa limpia. (It's a clean house — well kept, in general.) La casa está limpia. (The house is clean — someone just cleaned it.)

The right column often has a cause you could name if asked — the exam made him nervous, the coffee cooled, someone cleaned the house — and that's the thread linking a plain adjective like cansado to a past participle like roto. But estar doesn't require a nameable cause: El niño está enfermo (The child is sick) or María está casada (María is married) are states too, with no "something happened just now" implied.

Common mistakes

  • ❌ La puerta es abierta. → ✅ La puerta está abierta. (a result/state, not an identity)
  • ❌ Está una persona nerviosa. → ✅ Es una persona nerviosa. (a defining trait, not a momentary state)
  • ❌ El café es frío (meaning it cooled down) → ✅ El café está frío. (✅ Es frío is only right when the coldness is presented as a general, characteristic property, like El agua del grifo es fría en esta ciudad, the tap water in this city being cold in general.)
  • ❌ Estoy una persona cansada. → ✅ Soy una persona cansada (if it's just how you are) or Estoy cansada (if it's how you feel right now) — estar doesn't take una persona, only the adjective.

Quick check

Ser or estar?

  1. Mi hermano ___ muy tranquilo (as a person, always calm).
  2. La ventana ___ rota (someone broke it).
  3. Este actor ___ muy famoso.
  4. La leche ___ fría (it just came out of the fridge).
  5. Yo ___ preocupado por el examen de mañana.
Show answers
  1. Mi hermano es muy tranquilo. (defining trait)   2. La ventana está rota. (result of a change)   3. Este actor es muy famoso. (defining trait)   4. La leche está fría. (current state)   5. Yo estoy preocupado por el examen de mañana. (current state)

Key takeaways

  • With an adjective, ser presents a defining characteristic; estar presents a current state — including a state that's the result of some change.
  • Many past participles (roto, abierto, cerrado, cansado, perdido…) work as estar adjectives naming exactly that kind of result, agreeing in gender and number.
  • An adjective that looks like a personality trait can still take estar when it's describing a state, not how someone generally is: nervioso por el examen, contento con su trabajo.
  • Many estar states do trace back to a cause — a coffee that cooled, a door someone opened — but not all of them: estar enfermo, estar casado are states too, with no recent trigger implied.