The Type 1 conditional is the everyday workhorse for talking about things that genuinely might happen — tomorrow's weather, a possible plan, a request that the listener might or might not honour, a warning about a near-future consequence. The condition is treated as a real, live possibility, not a hypothesis. Si llueve mañana, no saldremos. Si tienes tiempo, llámame. Si me ayudas, te invito a una caña. The shape is straightforward: present indicative in the si-clause, and one of four shapes in the main clause.
This is the conditional you'll use most often once you're past the first few weeks of Spanish. It pairs with the future, with ir a, with the imperative, and even — for very near or planned events — with the present indicative. Each of those gives the sentence a slightly different flavour, and choosing among them is one of the small ways advanced learners sound more native.
The structure
| Si-clause | Main clause | Use |
|---|---|---|
| present indicative | future | predicted real future |
| present indicative | ir a | near-future plan or warning |
| present indicative | imperative | conditional request or instruction |
| present indicative | present indicative | very near future / planned event |
Notice that the si-clause is always in the present indicative. This is non-negotiable. The four main-clause options give you stylistic flexibility, but the si-clause is locked.
Main-clause option 1: future tense
The simple future (saldré, llamaré, iremos) is the most common main-clause shape for genuine predictions. The speaker is making a claim about what will happen if the condition holds.
Si llueve mañana, no saldremos a la sierra.
If it rains tomorrow, we won't go out to the mountains.
Si apruebas el examen, te invitaré a cenar a ese sitio que te gusta.
If you pass the exam, I'll take you out to dinner at that place you like.
Si llegamos antes de las ocho, podremos coger el último cercanías.
If we arrive before eight, we'll be able to catch the last commuter train.
The future tense in the main clause is the most "neutral" option and the default in writing. It frames the consequence as a forecast.
Main-clause option 2: ir a + infinitive
Ir a + infinitive is the colloquial near-future, especially common when the consequence feels imminent or when the speaker is delivering a warning.
Si sigues comiendo así, te vas a poner enfermo.
If you keep eating like this, you're going to get sick.
Si no te das prisa, vamos a perder el tren.
If you don't hurry up, we're going to miss the train.
Si llueve esta tarde, nos vamos a quedar en casa viendo una peli.
If it rains this afternoon, we're going to stay home watching a film.
The ir a form feels slightly more conversational than the simple future and is the unmarked choice in casual speech in Spain. Si llueve, no saldremos and si llueve, no vamos a salir mean the same thing; the second is just chattier.
Main-clause option 3: imperative
Type 1 with an imperative main clause is the standard shape for conditional requests, instructions, and offers. The condition gates the action: if X happens, then do Y.
Si tienes un momento, pásate por mi despacho antes de comer.
If you have a moment, drop by my office before lunch.
Si ves a Marta, dile que la estoy buscando.
If you see Marta, tell her I'm looking for her.
Si os apetece un café, decídmelo y os preparo uno.
If you fancy a coffee, let me know and I'll make you one.
Note the use of vosotros in the third example (decídmelo) — characteristic peninsular Spanish for plural informal address. In Latin American Spanish, you would say díganmelo.
Imperative + si is also the natural home for warnings: si haces eso, te vas a hacer daño leans toward the ir a form, but the imperative variant si oyes ruido raro, llámame is equally natural for protective instructions.
Main-clause option 4: present indicative for near-future plans
Spanish, like English, lets you use the present indicative for events that are scheduled or imminent. In Type 1, this happens when the consequence is something you're committing to do now, not something you're predicting.
Si quieres, te ayudo con la mudanza este sábado.
If you want, I'll help you with the move this Saturday.
Si te apetece, vamos al cine luego.
If you fancy it, we'll go to the cinema later.
Si me das diez minutos, lo arreglo.
If you give me ten minutes, I'll fix it.
The present-indicative main clause feels especially natural for offers and promises: the speaker is committing to act, not just predicting. Note that English often uses I'll here too — there's no neat English equivalent of the "present-as-near-future" usage in Spanish, since English's will is doing double duty as both a prediction marker and a volitional marker. Spanish keeps them more separate.
Subtypes by speech act
The same Type 1 skeleton supports several distinct speech acts. Pin these down and you'll recognise Type 1 in the wild:
Prediction. Si hace bueno mañana, iremos a la playa.
Polite request. Si tienes un momento, ¿podrías echarme una mano con esto?
Promise. Si me ayudas con la mudanza, te invito a cenar.
Threat (colloquial). Si vuelves a hacer eso, te juro que…
Warning. Si sigues así, te vas a hacer daño.
Offer. Si quieres, te llevo en coche.
Conditional instruction. Si oyes ruido, llámame inmediatamente.
All seven of these are Type 1; all seven use si + present indicative.
Si me ayudas con la mudanza, te invito a cenar el sábado.
If you help me with the move, I'll take you out to dinner on Saturday.
Si oyes algún ruido raro, llámame inmediatamente.
If you hear any strange noise, call me immediately.
Tú vs vosotros in peninsular Type 1
Peninsular Spanish makes regular use of vosotros/vosotras — the second-person plural informal pronoun — that other dialects lack. In Type 1 sentences addressed to a group of friends or family, the vosotros forms appear in both the si-clause and the main clause.
Si llegáis tarde, no os esperamos para empezar a cenar.
If you (all) arrive late, we won't wait for you to start dinner.
Si os apetece quedaros a comer, hay paella de sobra.
If you (all) feel like staying for lunch, there's plenty of paella.
Si tenéis dudas, preguntad sin problema.
If you (all) have any doubts, just ask, no problem.
Note the imperative preguntad in the third example — the vosotros affirmative imperative, which in casual peninsular speech is often replaced by the infinitive (preguntar), though preguntad is the standard form. The negative vosotros imperative uses the present subjunctive (si tenéis dudas, no me preguntéis en clase).
Sequencing and the comma
Like all conditional sentences in Spanish, the si-clause can come first or second.
Si llueve mañana, no saldremos.
If it rains tomorrow, we won't go out. (si-clause first — comma)
No saldremos si llueve mañana.
We won't go out if it rains tomorrow. (main clause first — no comma)
Fronting the si-clause foregrounds the condition; putting the main clause first foregrounds the consequence. In writing, the comma rule is strict: comma after a fronted si-clause, no comma before a final si-clause.
Si vs cuando in Type 1
In Type 1, si and cuando are not as freely interchangeable as in Type 0, because Type 1 is about a specific possible occasion.
- si llueve mañana = if it rains (it might, it might not)
- cuando llueva mañana = when it rains (treated as certain, with the subjunctive because it's a future cuando-clause)
Si llueve mañana, nos quedamos en casa.
If it rains tomorrow, we'll stay home. (it might rain or not)
Cuando llueva mañana, nos quedamos en casa.
When it rains tomorrow, we'll stay home. (rain is taken as certain)
The cuando version sounds odd in this context unless rain has been forecast as a certainty. For genuine "if-conditions," Type 1 si is the only natural choice.
Common Mistakes
❌ Si lloverá mañana, no saldremos.
Wrong — the si-clause never takes the future. Spanish forbids 'si + future' even though English allows 'if + will' in some constructions (very rare anyway).
✅ Si llueve mañana, no saldremos.
If it rains tomorrow, we won't go out.
❌ Si tendría tiempo, te llamaría.
Wrong — the si-clause never takes the conditional either. (This sentence is also confusing Type 1 with Type 2.)
✅ Si tengo tiempo, te llamaré. (Type 1) / Si tuviera tiempo, te llamaría. (Type 2)
If I have time, I'll call you. / If I had time, I'd call you.
❌ Si llegarás tarde, llámame.
Wrong — same rule. Even when paired with an imperative, the si-clause must be present indicative.
✅ Si llegas tarde, llámame.
If you're going to be late, call me.
❌ Si tienes tiempo llámame.
Missing comma — when the si-clause is fronted, a comma separates it from the main clause.
✅ Si tienes tiempo, llámame.
If you have time, call me.
❌ Si veis a Marta, decirle que la estoy buscando.
Wrong vosotros imperative — the standard form is 'decidle' (or colloquially 'decirle' is heard but considered incorrect in writing).
✅ Si veis a Marta, decidle que la estoy buscando.
If you (all) see Marta, tell her I'm looking for her.
Key takeaways
- Type 1 conditionals describe real future possibilities. The si-clause is always in the present indicative.
- The main clause can be: future (prediction), ir a
- infinitive
- Never put the future or the conditional in the si-clause. This is the single rule that catches the most learner errors.
- In peninsular Spanish, address to a group uses vosotros in both clauses: si llegáis tarde, no os esperamos.
- The choice among the four main-clause shapes is stylistic: future is neutral, ir a is colloquial, imperative is for instructions, present is for personal commitments.
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- Oraciones condicionales: guía completaB1 — A full reference for Spanish conditional sentences — the four classical types plus mixed conditionals, organised by how real the speaker considers the condition: factual, real-future, hypothetical, or counterfactual.
- Condicionales tipo 0: verdades generalesA2 — Spanish zero conditionals describe general truths, habitual routines, and scientific facts. Both clauses sit in the present indicative; the 'si' is closer to 'whenever' than to 'if'.
- Condicionales tipo 2: hipotéticos presentesB1 — Spanish Type 2 conditionals describe hypothetical, unlikely, or contrary-to-fact present situations. The 'si'-clause takes the imperfect subjunctive; the main clause takes the simple conditional.
- Futuro simple: verbos regularesA2 — The Spanish simple future for regular verbs — endings -é, -ás, -á, -emos, -éis, -án attached to the whole infinitive, the accents that are obligatory on every form except nosotros, and why ir a + infinitive often wins in everyday peninsular speech.
- Imperativo afirmativo de tú: regularA1 — The simplest of all Spanish imperatives — for regular verbs the affirmative tú command is identical to the 3rd-person singular present indicative.