Agente y omisión del agente (by…)
En la voz pasiva podemos mencionar quién hace la acción con by + agente (by the police), pero muchas veces lo omitimos. Aquí verás cuándo usarlo y cuándo no.
1) Mapa rápido
Estructura básica de pasiva con agente:
Objeto → be + V3 (+ by + agente)
• The painting was painted by Picasso.
• The letters are delivered by a courier.
En la práctica, muchas pasivas no llevan “by…”. El agente se dice solo cuando añade información útil.
2) ¿Qué es el “agente” en la pasiva?
En una oración activa tenemos:
The police arrested the thief.
(Sujeto / agente) (verbo) (objeto)
En la pasiva:
The thief was arrested by the police.
(objeto → sujeto pasivo) (be + V3) (agente con by)
- El agente es la persona o cosa que realiza la acción.
- Se introduce con by en la voz pasiva.
- No es obligatorio mencionarlo.
3) Cuándo mencionar el agente con by…
Usamos by + agente cuando:
- El agente es importante o interesante:
• This book was written by a famous writer.
• The project was designed by our team. - Queremos destacar al responsable:
• The problem was caused by a software error.
• The song was performed by a local band. - Hay varios posibles agentes y queremos especificar cuál:
• The cake was made by my brother, not by my mother.
by + persona / organización / cosa: by the government, by the company, by the storm, etc.
4) Cuándo omitir el agente (sin by…)
En muchos casos, el agente se omite porque no es necesario.
A) Agente desconocido
• My car was stolen yesterday.
(No sabemos quién la robó → no usamos by someone.)
• The window was broken last night.
B) Agente obvio o general (people, they, the police…)
• The thief was arrested (by the police).
• The road is cleaned every morning.
• Taxes are collected every year.
En estos ejemplos se entiende quién lo hace (la policía, el gobierno, trabajadores…), así que no hace falta decirlo.
C) Foco en el resultado, no en la persona
• The new bridge was opened in 2019.
• The results will be announced tomorrow.
En noticias y avisos, lo importante suele ser qué pasó o qué pasará, no quién exactamente lo hace.
5) Activa vs pasiva con by: matices de foco
| Oración | Tipo | ¿En qué se enfoca? |
|---|---|---|
| The company created this app. | Activa | Foco en the company. |
| This app was created by the company. | Pasiva + by | Foco en this app; “by the company” es información extra. |
| People speak English here. | Activa | Foco en lo que hace “people”. |
| English is spoken here. | Pasiva (sin by) | Foco en English; “people” es general y se omite. |
Si quieres destacar el objeto (app, puente, resultados), usa pasiva. Si quieres destacar quién hizo algo, la activa suele ser más natural.
6) Errores comunes
| Incorrecto | Correcto | Por qué |
|---|---|---|
| *The book was written for J.K. Rowling.* | The book was written by J.K. Rowling. | Para el autor usamos by, no for. |
| *The thief was arrested from the police.* | The thief was arrested by the police. | Agente en pasiva → by, no from. |
| *The house was built by people.* | The house was built. / The house was built by a local company. | people es demasiado general → mejor omitir o especificar. |
| *English is spoken by people in Canada.* | English is spoken in Canada. | by people es obvio; sobra. |
| *The exam was made by the students.* | The exam was taken by the students. | En inglés, el examen se toma, no se “hace” con make. |
7) Mini-práctica
- Añade un agente con by donde sea natural:
a) This song was written _______ (Taylor Swift).
b) The report was prepared _______ (our manager).
c) The bridge was designed _______ (a famous architect).
d) The food is delivered _______ (a courier company). - Omite el agente si es obvio o general. Reescribe:
a) The thief was arrested by the police.
b) Taxes are collected by the government every year.
c) The streets are cleaned by workers every night.
d) The driver was fined by the police. - Decide: ¿con by o sin by? (escribe la oración completa):
a) Abrieron el museo en 2001. (government)
b) Este edificio fue diseñado (a very famous architect).
c) Mi bolso fue robado en el metro. (unknown)
d) La web fue creada (a small local company). - Corrige si es necesario:
a) The film was directed for a Mexican director.
b) English is spoken by people in many countries.
c) The exam was done by the students.
d) The car was repaired from the mechanic. - Traduce al inglés usando pasiva y decide si incluyes by o no:
a) El cuadro fue pintado por Frida Kahlo.
b) El ladrón fue arrestado ayer.
c) El edificio fue construido en 1920.
d) Las entradas fueron vendidas en pocas horas (por los fans).
e) La canción fue interpretada por una banda local.
Respuestas ejemplo:
1) a) by Taylor Swift b) by our manager c) by a famous architect d) by a courier company
2) a) The thief was arrested. b) Taxes are collected every year.
c) The streets are cleaned every night. d) The driver was fined.
3) a) The museum was opened in 2001. (sin by, agente general)
b) This building was designed by a very famous architect.
c) My bag was stolen on the subway. (agente desconocido, sin by)
d) The website was created by a small local company.
4) a) The film was directed by a Mexican director.
b) English is spoken in many countries.
c) The exam was taken by the students.
d) The car was repaired by the mechanic.
5) a) The painting was painted by Frida Kahlo.
b) The thief was arrested yesterday. (no hace falta by the police)
c) The building was built in 1920.
d) The tickets were sold in a few hours (by the fans).
e) The song was performed by a local band.
8) Próximo paso
Continúa con Reported speech: afirmaciones (backshift básico) para aprender a contar lo que alguien dijo usando cambios de tiempo como “I’m tired” → He said he was tired.