Tercer condicional (irreal en pasado)
"if + past perfect, would have + past participle. Unreal past hypotheses."
La regla
if + past perfect, would have + participio. Hipotesis irreales sobre el pasado.
El tercer condicional describe situaciones hipoteticas en el pasado que NO ocurrieron. Es la herramienta del lamento, el reproche y el análisis post-mortem: "If I had reviewed the logs, I would have caught the bug" (no los revise, no lo cogi). Estructura: if + past perfect (had + p.p.), would have + p.p. También puedes usar could have (habria podido) o might have (quizas habria) en la principal. Nunca uses would en la clausula del if.
Ejemplos
If I had studied harder, I would have passed.
Sí hubiera estudiado más, habria aprobado.
If we had reviewed the logs, we would have caught the bug.
Sí hubieramos revisado los logs, habriamos cogido el bug.
If Marta hadn't pushed to main, prod wouldn't have crashed.
Sí Marta no hubiera hecho push a main, prod no habria caido.
We could have shipped on Friday if the tests had passed.
Habriamos podido desplegar el viernes sí los tests hubieran pasado.
If I had used prompt caching, the eval would have been cheaper.
Sí hubiera usado prompt caching, la eval habria sido más barata.
She might have joined Nexora earlier if she had known about the role.
Quizas habria entrado en Nexora antes sí hubiera sabido del puesto.
If you had attended the retro, you would have heard the feedback.
Sí hubieras ido a la retro, habrias oido el feedback.
Casos típicos
Trampas hispanohablantes
NUNCA uses would en la clausula del if. Solo had + p.p.
Falta el have. La estructura es would HAVE + participio.
Tras had va el participio (reviewed), no el infinitivo.
Tercer condicional usa past perfect (had/hadn't) en el if.
La principal lleva WOULD have, no will have.