A conditional sentence is a sentence with an "if" clause (si-clause) and a result clause. Spanish organizes these into four main types, each with a characteristic pairing of tense and mood. Master these four types and you can express anything from general truths to impossible fantasies. This guide covers every type, plus mixed conditionals, como si, de + infinitive, and the most common alternative conditional conjunctions.
Before we start, a basic rule: in a Spanish si-clause referring to the present or future, you never use the present subjunctive after si. If you catch yourself writing si tengas, you've already made a mistake.
The Four Types at a Glance
| Type | Meaning | Si-clause tense | Result clause tense | Example |
|---|---|---|---|---|
| Type 0 | general truth | present indicative | present indicative | Si llueve, me quedo en casa. |
| Type 1 | real / probable future | present indicative | future / imperative / ir a + inf. | Si llueve, me quedaré en casa. |
| Type 2 | hypothetical present / unlikely future | imperfect subjunctive | conditional | Si lloviera, me quedaría en casa. |
| Type 3 | impossible past (contrary to fact) | pluperfect subjunctive | conditional perfect (or pluperfect subj.) | Si hubiera llovido, me habría quedado en casa. |
Notice the clean pattern: Type 0 and Type 1 stay in the indicative; Type 2 and Type 3 move to the subjunctive. The move to subjunctive is what marks unreality.
1. Type 0 — General Truths
Type 0 conditionals express things that are always or usually true. Both clauses are in the present indicative. You could paraphrase them with whenever or every time.
Formula: si + present indicative, present indicative.
Si hace frío, me pongo un abrigo.
If it's cold, I put on a coat.
Si estudias, aprendes.
If you study, you learn.
Si no comes, te enfermas.
If you don't eat, you get sick.
Si el agua hierve, produce vapor.
If water boils, it produces steam.
This type works for laws of nature, habitual behavior, and general rules. The result isn't a prediction about one specific future moment; it's what always happens. See Type 0 conditionals.
2. Type 1 — Real and Probable
Type 1 is the most common conditional in everyday speech. It covers real, probable future situations — things you believe might genuinely happen.
Formula: si + present indicative, {future / imperative / ir a + infinitive / present}.
The si-clause stays in the present indicative. The result clause can take several forms depending on what kind of consequence you're expressing.
| Result clause form | Example |
|---|---|
| future | Si llueve, me quedaré en casa. |
| ir a + infinitive | Si llueve, voy a quedarme en casa. |
| imperative | Si llueve, quédate en casa. |
| present (informal prediction) | Si llueve, me quedo en casa. |
Si tengo tiempo, te llamo esta noche.
If I have time, I'll call you tonight.
Si ves a María, dile que la extraño.
If you see María, tell her I miss her.
Remember: no present subjunctive after si in Type 1. Si estudies is ungrammatical. See Type 1 conditionals.
3. Type 2 — Hypothetical / Unlikely
Type 2 expresses situations that are hypothetical or contrary to fact in the present, or unlikely in the future. English renders it as "if I had / if I were / if I did" with the conditional "would".
Formula: si + imperfect subjunctive, conditional.
The imperfect subjunctive has two possible endings (-ra or -se); in Latin America, -ra forms are overwhelmingly preferred.
| Infinitive | Imperfect subjunctive (-ra) | Conditional |
|---|---|---|
| tener | tuviera / tuvieras / tuviera / tuviéramos / tuvieran | tendría / tendrías / tendría / tendríamos / tendrían |
| ser | fuera / fueras / fuera / fuéramos / fueran | sería / serías / sería / seríamos / serían |
| ir | fuera / fueras / fuera / fuéramos / fueran | iría / irías / iría / iríamos / irían |
| poder | pudiera / pudieras / pudiera / pudiéramos / pudieran | podría / podrías / podría / podríamos / podrían |
| estudiar | estudiara / estudiaras / estudiara / estudiáramos / estudiaran | estudiaría / estudiarías / estudiaría / estudiaríamos / estudiarían |
Si tuviera más tiempo, viajaría por todo el mundo.
If I had more time, I'd travel all over the world.
Si fuera rico, me compraría una casa en la playa.
If I were rich, I'd buy myself a beach house.
Si supiera la respuesta, te la diría.
If I knew the answer, I'd tell you.
¿Qué harías si ganaras la lotería?
What would you do if you won the lottery?
You can also reverse the order of the clauses without changing meaning: Viajaría por todo el mundo si tuviera más tiempo.
Type 2 is the form to use for polite hypothetical questions and dreams / wishes / daydreams. See Type 2 conditionals.
4. Type 3 — Impossible Past (Contrary to Fact)
Type 3 describes situations that didn't happen in the past — regrets, counterfactual reflections, alternative histories. English renders it as "if I had done... I would have done...".
Formula: si + pluperfect subjunctive, conditional perfect.
The pluperfect subjunctive = hubiera / hubieras / hubiera / hubiéramos / hubieran + past participle. The conditional perfect = habría / habrías / habría / habríamos / habrían + past participle.
Si hubiera estudiado más, habría aprobado el examen.
If I had studied more, I would have passed the exam.
Si me hubieras llamado, te habría ayudado.
If you had called me, I would have helped you.
Si hubiéramos salido a tiempo, no habríamos perdido el vuelo.
If we had left on time, we wouldn't have missed the flight.
Si hubiera sabido, no habría venido.
If I had known, I wouldn't have come.
A very common Latin American variant: the result clause uses the pluperfect subjunctive instead of the conditional perfect, especially in speech. Both are considered correct.
Si hubiera estudiado más, hubiera aprobado el examen.
If I had studied more, I would have passed the exam. (equally common in LatAm speech)
See Type 3 conditionals.
5. Mixed Conditionals
Spanish freely mixes Types 2 and 3 when the time of the condition and the time of the result don't match.
Past condition, present result
"If I had studied medicine (in the past), I would be a doctor now (in the present)."
Formula: si + pluperfect subjunctive, conditional.
Si hubiera estudiado medicina, sería doctor.
If I had studied medicine, I would be a doctor.
Si no me hubiera casado tan joven, viviría en otro país.
If I hadn't married so young, I'd live in another country.
Present condition, past result
"If I were more organized (in general), I would have finished by now."
Formula: si + imperfect subjunctive, conditional perfect.
Si fuera más organizado, ya habría terminado el trabajo.
If I were more organized, I would have already finished the job.
See mixed conditionals.
6. Como si — Always Counterfactual
Como si ("as if, as though") introduces a counterfactual comparison. The clause after como si always takes either the imperfect subjunctive (simultaneous or present reference) or the pluperfect subjunctive (prior reference). Never use present indicative or present subjunctive after como si.
Habla como si supiera todo.
He talks as if he knew everything.
Me miró como si nunca me hubiera visto antes.
She looked at me as if she had never seen me before.
Se comporta como si fuera el jefe.
He acts as if he were the boss.
Parecía como si hubiera llorado toda la noche.
It looked as if she had cried all night.
The choice between imperfect and pluperfect subjunctive depends on whether the imagined event is simultaneous with the main verb (imperfect) or earlier than it (pluperfect). See como si.
7. De + Infinitive — A Conditional Alternative
You can replace many si-clauses with de + infinitive, especially in Type 2 and Type 3 contexts. It's a condensed, slightly more formal way of expressing the same idea.
| Si-clause | De + infinitive equivalent |
|---|---|
| Si yo tuviera tiempo, iría. | De tener tiempo, iría. |
| Si lo hubiera sabido, habría llamado. | De haberlo sabido, habría llamado. |
| Si no fuera tan tarde, te invitaría. | De no ser tan tarde, te invitaría. |
| Si sigues así, fracasarás. | De seguir así, fracasarás. |
De haberlo sabido, no habría venido.
Had I known, I wouldn't have come.
De tener más dinero, viajaría más.
If I had more money, I'd travel more.
This is especially common in writing and in formal speech. See de + infinitive.
8. Other Conditional Conjunctions
Spanish has a whole family of conjunctions of condition that require the subjunctive in the clause they introduce. Each carries its own nuance.
| Conjunction | Meaning | Example |
|---|---|---|
| a menos que | unless | Iré a menos que llueva. |
| con tal de que | provided that | Te lo presto con tal de que me lo devuelvas. |
| en caso de que | in case (that) | Lleva paraguas en caso de que llueva. |
| siempre y cuando | as long as / provided | Iré siempre y cuando me acompañes. |
| a condición de que | on the condition that | Acepto a condición de que paguen antes. |
| salvo que / excepto que | unless / except that | Vendré salvo que me llames para cancelar. |
| mientras (que) | as long as | Puedes quedarte mientras no molestes. |
Te ayudaré con tal de que me digas la verdad.
I'll help you provided that you tell me the truth.
Saldremos a menos que haga mal tiempo.
We'll go out unless the weather is bad.
Lleva algo de dinero en caso de que lo necesites.
Take some money in case you need it.
Puedes salir siempre y cuando vuelvas antes de las once.
You can go out as long as you come back before eleven.
All of these conjunctions take the subjunctive — present subjunctive for present/future reference, imperfect subjunctive for hypothetical cases. See other conditional expressions.
9. Side-by-Side Master Comparison
| Type | Si clause | Result clause | Feels like... |
|---|---|---|---|
| Type 0 (general) | Si + presente | presente | always / whenever |
| Type 1 (real future) | Si + presente | futuro / imperativo / ir a + inf. | might really happen |
| Type 2 (hypothetical) | Si + imperfecto de subjuntivo | condicional | not true now / unlikely |
| Type 3 (counterfactual past) | Si + pluscuamperfecto de subjuntivo | condicional perfecto (o pluscuamperfecto) | didn't happen — regret |
| Mixed (past → present) | Si + pluscuamperfecto de subjuntivo | condicional | past cause, present result |
| Mixed (present → past) | Si + imperfecto de subjuntivo | condicional perfecto | present state, past result |
| Como si | imperfecto / pluscuamperfecto de subjuntivo | any tense | as if, never true |
10. Common Errors
| Wrong | Right | Why |
|---|---|---|
| *Si tengas tiempo, llámame. | Si tienes tiempo, llámame. | Never present subjunctive after si (present/future) |
| *Si tendría dinero, lo compraría. | Si tuviera dinero, lo compraría. | Conditional never in si-clause; use imperfect subjunctive |
| *Si habría estudiado, aprobaría. | Si hubiera estudiado, habría aprobado. | Conditional perfect never in si-clause |
| *Habla como si sabe todo. | Habla como si supiera todo. | Como si always requires subjunctive |
| *A menos que vienes | A menos que vengas | A menos que always takes subjunctive |
| *Si yo fuera tú, voy. | Si yo fuera tú, iría. | Type 2 pairs imperfect subjunctive with conditional |
11. Putting It Together
Si quieres, te ayudo con la tarea.
If you want, I'll help you with the homework. (Type 1, casual)
Si lo hubiera sabido antes, no habría dicho nada.
If I had known earlier, I wouldn't have said anything. (Type 3)
Si hubiera nacido en otro país, hablaría otro idioma.
If I had been born in another country, I'd speak a different language. (Mixed: past → present)
De haber ganado el premio, lo habríamos donado.
Had we won the prize, we would have donated it. (De + infinitive = Type 3)
Iré contigo siempre y cuando me prometas llegar a tiempo.
I'll go with you as long as you promise to arrive on time.
Summary
- Type 0: general truths — si + present, present.
- Type 1: real possibilities — si + present, future / imperative / ir a + inf.
- Type 2: hypothetical or unlikely — si + imperfect subjunctive, conditional.
- Type 3: impossible past — si + pluperfect subjunctive, conditional perfect (or pluperfect subjunctive in LatAm speech).
- Mixed conditionals combine Type 2 and Type 3 tenses when condition and result refer to different times.
- Como si always takes the imperfect or pluperfect subjunctive, never the indicative.
- De + infinitive is a compact alternative to si-clauses, especially in Types 2 and 3.
- Other conditional conjunctions — a menos que, con tal de que, en caso de que, siempre y cuando, a condición de que, salvo que, mientras — all require the subjunctive.
- Never use the present subjunctive or the conditional directly inside a si-clause.
With these rules internalized, you can express any conditional relationship Spanish allows — from everyday "if it rains" to philosophical "had we only known".
Related Topics
- Type 0: General TruthsA2 — Pair a present-tense si-clause with a present-tense result clause to state facts, laws, and habits that are always true.
- 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.
- Mixed ConditionalsC1 — Combine past and present in a single conditional to talk about how what didn't happen then still shapes how things are now.
- Como Si (As If)B2 — The expression como si always takes the imperfect or pluperfect subjunctive — never the present.
- De + Infinitive ConditionalB2 — An alternative to si-clauses: de followed by an infinitive expresses the same condition in a more formal or literary register.
- Other Conditional ExpressionsB2 — A family of conjunctions — a menos que, con tal de que, en caso de que, and more — all express conditions and all require the subjunctive.
- Imperfect Subjunctive: -Ra FormsB2 — Learn how to form the imperfect subjunctive using the -ra endings, the most common form in Latin American Spanish.
- Pluperfect Subjunctive: FormationC1 — Learn to form the pluperfect subjunctive with haber plus the past participle.
- Regular FormationB1 — Form the Spanish conditional by adding -ía endings to the full infinitive of any regular verb.