"Dead" is the state of being lifeless (adjective); "died" is the act of dying (past tense verb).
Without life. Adjective describing a state. Can describe people, animals, plants, or things.
The plant is dead. I forgot to water it for two weeks.
La planta esta muerta. Olvide regarla por dos semanas.
My phone battery is dead. Do you have a charger?
La bateria de mi telefono esta muerta. ¿Tienes un cargador?
The ancient king has been dead for over 2000 years.
El antiguo rey ha estado muerto por mas de 2000 anos.
Ceased to live. Past simple of the verb "die". Describes the event of dying.
My grandfather died in 1998 at the age of 87.
Mi abuelo murio en 1998 a la edad de 87 anos.
Three people died in the accident on the highway.
Tres personas murieron en el accidente en la autopista.
He died doing what he loved — flying.
Murio haciendo lo que amaba: volar.
Common mistake
Saying "He is died" or treating "dead" as a verb: neither works. "Dead" is an adjective and takes "to be": "He is dead." "Died" is a verb and stands alone or with auxiliaries: "He died." "He is died" mixes both systems and is wrong. Another error: "He died since 1990" — wrong; correct is "He died in 1990" or "He has been dead since 1990".
Trick to remember it
Useful parallel: asleep (state) / fell asleep (event). Dead (state) / died (event). Just as you would not say "he is fell asleep", you do not say "he is died". State uses "be + adjective"; event uses the verb alone.
Quick rule
Dead = being lifeless (adjective, with "be"). Died = to die (verb, past event).
Did you know?
"Dead" has enormous colloquial richness: "deadpan" (expressionless), "deadline" (due date — literally "death line"), "dead end" (no way through), "dead heat" (exact tie), "drop dead gorgeous" (strikingly attractive). "Deadline" comes from 19th-century journalism: if text passed that line on the printing plate, it was too late to include — it was "dead".
Exercise 1 · Pick the right one
Her favorite author _____ before she was born, but she loves his books.
Exercise 2 · Pick the right one
Be careful — that tree is _____. A branch could fall at any moment.
Exercise 3 · Form the word
Dead = being lifeless (adjective, with "be"). Died = to die (verb, past event).
Saying "He is died" or treating "dead" as a verb: neither works. "Dead" is an adjective and takes "to be": "He is dead." "Died" is a verb and stands alone or with auxiliaries: "He died." "He is died" mixes both systems and is wrong. Another error: "He died since 1990" — wrong; correct is "He died in 1990" or "He has been dead since 1990".
Useful parallel: asleep (state) / fell asleep (event). Dead (state) / died (event). Just as you would not say "he is fell asleep", you do not say "he is died". State uses "be + adjective"; event uses the verb alone.
Bryan López
Founder of SpeakUP Academy