Spanish has a compact, written-register alternative to si-clauses: de + infinitive. De haber sabido, habría venido means exactly the same thing as si hubiera sabido, habría venido — "had I known, I would have come" — but packages the protasis into a non-finite phrase. The structure shows up everywhere in journalism, op-eds, business prose, and political speech, but is almost never heard in casual conversation. Learning to recognise it (and to deploy it sparingly) is part of moving from B1 to a working command of formal Spanish.
This page covers the construction in full: what it is, when to use it, the two flavours (present and perfect), the implicit-subject trap, register, and the mistakes English-speakers make.
The construction
In a regular conditional sentence, the protasis is a full clause introduced by si with a finite (conjugated) verb. The alternative is to replace that finite clause with de + infinitive (present or perfect), leaving the main clause untouched.
| Regular conditional | De + infinitivo equivalent |
|---|---|
| Si fuera verdad, sería increíble. | De ser verdad, sería increíble. |
| Si lo supiera, te lo diría. | De saberlo, te lo diría. |
| Si hubiera sabido eso, habría venido antes. | De haber sabido eso, habría venido antes. |
| Si no hubiera llegado a tiempo, habríamos perdido el vuelo. | De no haber llegado a tiempo, habríamos perdido el vuelo. |
The structure is mechanical: take the si-clause, replace si with de, and convert the finite verb to an infinitive (present infinitive for hypothetical present, perfect infinitive for counterfactual past). The main clause keeps the conditional or conditional-perfect form it already had.
The two flavours
De + present infinitive — present/future hypothetical
Replaces si + imperfect subjunctive. The condition is a hypothesis about the present or a non-specific future.
De ser verdad lo que dices, sería un escándalo.
If what you're saying were true, it'd be a scandal.
De aprobar el examen, podría matricularme en Medicina.
If I were to pass the exam, I could enrol in Medicine.
De no aceptar la oferta, perdería una oportunidad única.
If she didn't accept the offer, she'd be missing a unique opportunity.
These map directly onto Type 2 (hypothetical) conditionals: si fuera verdad → de ser verdad, si aprobara → de aprobar. Notice that Spanish doesn't distinguish "if I pass" from "if I were to pass" inside the de-construction — context disambiguates.
De haber + participle — counterfactual past
Replaces si + pluperfect subjunctive. The condition is a counterfactual past: something that didn't actually happen.
De haber sabido que venías, habría preparado la cena.
Had I known you were coming, I would have made dinner.
De haber llegado cinco minutos antes, habríamos cogido el tren.
If we'd arrived five minutes earlier, we would have caught the train.
De no haber sido por tu ayuda, no lo habría conseguido nunca.
If it hadn't been for your help, I'd never have managed it.
The perfect infinitive (haber + past participle) is non-negotiable here. De saber and de haber sabido mean different things — present hypothetical vs. counterfactual past — and learners frequently confuse them. De saber que venías, habría preparado la cena is grammatically real Spanish, but it means something subtly different and feels wrong in this counterfactual-past context. Stick to de haber + participle whenever the result is habría + participle.
Register: where this lives
De + infinitive is formal, written, often journalistic. You will find it constantly in newspaper headlines, leader articles, opinion columns, business reports, political speech, and any prose aiming for concision and a touch of formality. You will almost never hear it in casual conversation.
Headlines love this structure because it compresses two clauses into one phrase, saving space:
De confirmarse el dato, el paro habría caído por debajo del 10% por primera vez en una década.
If the figure is confirmed, unemployment would have dropped below 10% for the first time in a decade.
De prosperar el recurso, el fallo del tribunal quedaría anulado.
If the appeal succeeds, the court's ruling would be overturned.
De no mediar un acuerdo de última hora, la huelga afectará a 15 000 trabajadores.
If no last-minute agreement is reached, the strike will affect 15,000 workers.
Opinion writing uses the construction for rhetorical balance:
De haber actuado el Gobierno con mayor rapidez, muchas de estas consecuencias podrían haberse evitado.
Had the government acted more swiftly, many of these consequences could have been avoided.
In conversation, de + infinitive almost always sounds stilted and bureaucratic. De haber sabido, habría venido in a normal chat sounds like you're addressing parliament. The plain si hubiera sabido, habría venido is the everyday equivalent.
The implicit-subject trap
This is where learners most often slip. Because the infinitive has no person marking, the subject of the de-clause is whatever the surrounding context implies — most often the subject of the main clause.
De aprobar el examen, seré médico.
If I pass the exam, I'll be a doctor. (subject of 'aprobar' = yo, inferred from 'seré')
De terminar a tiempo, podríamos ir al cine.
If we finished on time, we could go to the cinema. (subject = nosotros, from 'podríamos')
When the two clauses have different subjects, the de-construction becomes ambiguous or unusable, and you fall back to the si-clause:
❌ De aprobar el examen, te invitaré a cenar.
Confusing — who is taking the exam, me or you? The implicit subject is unclear.
✅ Si apruebas el examen, te invitaré a cenar.
If you pass the exam, I'll take you out to dinner. (clearer with si)
There is one exception: when the de-clause carries an explicit subject itself (typical in formal/journalistic writing with impersonal subjects), the construction works fine.
De confirmarse el dato por el Banco de España, el paro habría caído por debajo del 10%.
If the figure is confirmed by the Bank of Spain, unemployment would have dropped below 10%. (subject of 'confirmarse' = el dato)
Here the reflexive confirmarse takes el dato as its subject, anchored by the agent phrase por el Banco de España. This is a journalistic register feature; learn to recognise it.
Position and word order
The de-clause almost always precedes the main clause. The natural rhythm of the construction is condition → result, and inverting feels heavy.
De haber llegado antes, lo habríamos visto.
Had we arrived earlier, we would have seen him. (natural)
Lo habríamos visto, de haber llegado antes.
We would have seen him, had we arrived earlier. (possible but heavy)
The fronted de-clause functions as a topic that sets up the hypothesis, and the main clause delivers the consequence. In journalism the fronted position is almost categorical.
Negation
Negation sits between de and the infinitive: de no + infinitive, or de no haber + participle.
De no haber llegado a tiempo, habríamos perdido el vuelo.
Had we not arrived on time, we'd have missed the flight.
De no firmar el contrato hoy, perderás el descuento.
If you don't sign the contract today, you'll lose the discount.
De no ser por su intervención, todo habría salido mal.
If it hadn't been for his intervention, everything would have gone wrong.
The last one — de no ser por + noun — is a particularly common fixed expression in peninsular formal Spanish, equivalent to English if it weren't for / if it hadn't been for.
Two close relatives: a + infinitive and con + infinitive
For completeness: Spanish has two related constructions that compress conditions into non-finite phrases, but with different meanings.
- A + infinitive — a juzgar por... (judging by) — a fixed-phrase use, not a productive conditional.
- Con + infinitive — con saber un poco, te las arreglas (knowing a little is enough to get by) — expresses sufficiency, closer to "as long as" than to "if".
Con llegar a las siete es suficiente, no te apures.
As long as you get there by seven, you're fine, don't rush.
These deserve their own page but should not be confused with the de + infinitive structure, which is a pure substitute for si-clauses.
Compact comparison
| Form | Equivalent to | Register | Example |
|---|---|---|---|
de
| si
| formal / journalistic | De ser verdad, sería un escándalo. |
de haber
| si
| formal / journalistic | De haber sabido, habría venido. |
de no
| si no
| formal / journalistic | De no firmar hoy, pierdes el descuento. |
de no haber
| si no
| formal / journalistic | De no haber llegado, habríamos perdido el vuelo. |
Common Mistakes
❌ De sabía que venías, habría preparado la cena.
Wrong — de is followed by an infinitive, never a conjugated form. ('Sabía' is the imperfect indicative.)
✅ De haber sabido que venías, habría preparado la cena.
Had I known you were coming, I'd have made dinner.
❌ De saber que venías, habría preparado la cena.
Almost right, but the perfect-infinitive 'haber sabido' is required because the result is in the conditional perfect (counterfactual past).
✅ De haber sabido que venías, habría preparado la cena.
Had I known you were coming, I'd have made dinner.
❌ De aprobar el examen, te invitaré a cenar.
Subject mismatch — who's taking the exam? The implicit subject is unclear because the main clause is about 'yo' and the protasis presumably about 'tú'.
✅ Si apruebas el examen, te invitaré a cenar.
If you pass the exam, I'll take you out to dinner.
❌ Si de haber sabido que venías, habría preparado la cena.
Don't stack 'si' and 'de' — they're two different ways of marking the protasis. Use one or the other.
✅ De haber sabido que venías, habría preparado la cena.
Had I known you were coming, I'd have made dinner.
❌ De ser verdad, sería increíble, ¿no crees?
Grammatically fine, but stylistically jarring in casual conversation — the formal register clashes with the conversational tag. Use 'si fuera verdad' in chat.
✅ Si fuera verdad, sería increíble, ¿no crees?
If it were true, it'd be incredible, don't you think? (everyday register)
Key takeaways
- De
- infinitive is a formal, written-register alternative to si-clauses. Recognise it in journalism, op-eds, and political speech; use it sparingly.
- Two flavours: de
- present infinitive (hypothetical present) and de haber
- participle (counterfactual past). Match the flavour to the result tense: simple conditional pairs with present infinitive; conditional perfect pairs with perfect infinitive.
- present infinitive (hypothetical present) and de haber
- The implicit subject of the de-clause comes from the main clause. If subjects differ, fall back to si
- finite verb — except in journalistic style where the de-clause carries its own explicit subject (de confirmarse el dato...).
- The de-clause almost always precedes the main clause.
- De no ser por... (if it weren't for...) is a high-frequency fixed expression in formal Spanish.
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Start learning Spanish→Related Topics
- Condicionales mixtosB2 — Mixed conditionals combine a past hypothetical with a present consequence, or a present trait with a past outcome — built by matching each clause's tense to the time it lives in, not by fixed pairings.
- Como si: estructura comparativa hipotéticaB1 — Como si ('as if') compares a real situation to a hypothetical one, and always forces the imperfect or pluperfect subjunctive — never the indicative, never the present subjunctive.
- Otras expresiones condicionales: a menos que, salvo queB2 — Beyond si: a family of conjunctions — a menos que, salvo que, en caso de que, con tal de que, siempre que, mientras, como — express conditional ideas with their own moods and nuances.
- Infinitivo después de verbos conjugadosA2 — When two verbs share a subject, the second one stays in the infinitive — quiero ir, puedo venir, suelo madrugar — never que, never a conjugated form.
- Usos del condicional compuestoB2 — When to use the conditional perfect (habría hablado) — past counterfactuals, unrealised intentions, and reported future-perfect.
- Infinitivo compuesto: 'haber + participio'B2 — The perfect infinitive (haber + participle) — how Spanish expresses prior action in non-finite contexts after verbs, prepositions, and connectors.