Español — Conditional of probability
The simple conditional expresses a guess or estimate about the past: Serían las tres cuando llegó means the speaker supposes it was around three o'clock, not a certainty.
How it works
Just as the future can express a guess about the present (Serán las tres), the simple conditional shifts that conjecture to the past: Serían las tres cuando llegó (≈ it was probably three) and Tendría unos veinte años (≈ he was about twenty). The verb takes normal conditional endings; the doubt comes from the tense itself, not from any added word.
Examples
| Conditional (conjecture) | Interpretation |
|---|---|
| Serían las tres cuando llegó. | It was probably around three when he arrived. |
| Tendría unos veinte años. | He was probably about twenty. |
| ¿Quién llamaría a esa hora? | Who could have been calling at that hour? |
| Estaría cansada y por eso se fue. | She must have been tired, and that's why she left. |
| Costaría unos cincuenta euros. | It probably cost about fifty euros. |
| No sé, serían las diez pasadas. | I'm not sure — it must have been just after ten. |
Good to know
Match the tense to the moment you are guessing about. Use the future for a guess about now (Serán las tres = it's probably three), but the simple conditional for a guess about the past (Serían las tres = it was probably three). For a completed past action, use the conditional perfect instead: Habrían llegado ya (they had probably already arrived).