Spanish has a compact alternative to the si-clause: the preposition de followed by an infinitive. The de-infinitive phrase replaces the whole si + conjugated verb construction and gives the sentence a more formal, literary, or journalistic flavor. It is common in writing and in polished speech, but it is less frequent in casual conversation.
The basic pattern
Take a si-clause, strip out si, drop the conjugated verb, and swap in de + infinitive. The result clause stays exactly the same.
Structure: De + infinitive, result clause.
De saberlo, te habría llamado.
If I had known, I would have called you.
Compare each one to its si-clause cousin:
- De saberlo = Si lo hubiera sabido
- De tener tiempo = Si tuviera tiempo
The de-infinitive form is shorter, but it carries all the same meaning. The tense of the result clause tells you whether the condition refers to the present or to the past.
Telling present from past
Because the infinitive itself doesn't carry tense, you have to look at the result clause to figure out whether the condition is hypothetical now or contrary-to-fact in the past.
De ganar la lotería, compraría una casa en la playa.
If I won the lottery, I would buy a house at the beach.
De haber ganado la lotería, habría comprado una casa en la playa.
If I had won the lottery, I would have bought a house at the beach.
Adding haber to the infinitive shifts everything into the past. The first sentence is a type 2 conditional; the second is a type 3 conditional.
Why writers love it
The de-infinitive construction is especially common in news writing, legal language, and literary prose because it is compact and elegant. It also puts the condition up front in a way that feels more crisp than a full si-clause.
De continuar esta tendencia, la economía entrará en recesión.
If this trend continues, the economy will enter a recession.
De no encontrarse una solución, el proyecto será cancelado.
If a solution isn't found, the project will be canceled.
These sentences sound completely natural in a newspaper article or an official announcement. You would rarely say them out loud during lunch — the si-clause version would feel more appropriate there.
Negative conditions
To negate a de-infinitive clause, place no between de and the infinitive.
De no haber llegado a tiempo, habríamos perdido el vuelo.
If we hadn't arrived on time, we would have missed the flight.
De no ser por tu ayuda, no lo habría logrado.
If it weren't for your help, I wouldn't have managed it.
The expression de no ser por... ("if it weren't for...") is a fixed phrase worth learning as a unit. It shows up constantly in thank-you speeches and reflective passages.
When to stick with si
Don't reach for the de-infinitive in casual speech. It can sound stiff or old-fashioned if the context is a friendly conversation.
| Register | Typical choice |
|---|---|
| Chat with a friend | si + subjunctive |
| Formal letter | either one works |
| News article | de + infinitive is common |
| Literary narration | de + infinitive is elegant |
Subject and de-infinitives
Since the infinitive has no conjugation, the subject of the de-clause has to be clear from context. Usually it matches the subject of the result clause, which makes the sentence tidy.
De haber sabido eso, yo no habría aceptado la invitación.
If I had known that, I wouldn't have accepted the invitation.
Related Topics
- Type 1: ProbableB1 — Use a present-tense si-clause with a future, imperative, or present result clause for situations that are likely to happen.
- Type 2: ImprobableB2 — Pair an imperfect-subjunctive si-clause with a conditional result clause for hypothetical or unlikely present situations.
- Type 3: Contrary-to-Fact PastC1 — Use the pluperfect subjunctive with the conditional perfect to talk about past situations that didn't actually happen.