An open conditional describes a condition that is genuinely possible — something that may well happen. "If it rains, I'll stay home." You are not fantasizing about an impossible world; you are stating a real plan that depends on a real, plausible condition. This is the first and most useful conditional to master, and Brazilian Portuguese handles it with a twist that trips up nearly every English speaker: when the condition is about the future, the verb in the se-clause must go into the future subjunctive (futuro do subjuntivo) — a tense English does not have.
Two kinds of open conditional
Open conditionals split into two based on when and how often the condition holds.
1. Habitual / general — present indicative
When the condition is a general truth or a recurring habit ("whenever X happens, Y happens"), use the present indicative in both clauses.
Se chove, eu fico em casa.
If it rains, I stay home. — a general habit: this is what I always do when it rains
Se você aperta esse botão, a luz acende.
If you press this button, the light turns on. — a general truth about how the thing works
Se ele bebe café à noite, não dorme.
If he drinks coffee at night, he doesn't sleep. — a recurring pattern
Here se means something close to "whenever" or "every time." The present indicative signals that you are describing reality as it regularly is.
2. Specific future — future subjunctive
When the condition refers to a specific future occasion ("if X happens [this time / tomorrow]"), the se-clause takes the future subjunctive, and the main clause takes a future-meaning form — usually the periphrastic future (vou + infinitive), the simple present with future sense, or an imperative.
Se chover amanhã, eu não vou à praia.
If it rains tomorrow, I won't go to the beach. — a specific future occasion: 'chover' is future subjunctive
Se você quiser, a gente vai junto.
If you want, we'll go together. — 'quiser' is the future subjunctive of querer
Se eu tiver tempo, eu te ajudo com a mudança.
If I have time, I'll help you with the move. — 'tiver' is the future subjunctive of ter
The future subjunctive: why it looks like the infinitive
Here is the trap. For regular verbs, the third-person singular of the future subjunctive is identical to the infinitive: chover (to rain / if it rains), falar (to speak / if he speaks), comer (to eat / if you eat). English speakers see se chover and assume chover is just the bare infinitive sitting there untranslated. It is not. It is a fully conjugated future subjunctive, and it changes for person:
| Person | falar (to speak) | comer (to eat) | partir (to leave) |
|---|---|---|---|
| eu | falar | comer | partir |
| você / ele / ela | falar | comer | partir |
| nós | falarmos | comermos | partirmos |
| vocês / eles | falarem | comerem | partirem |
The endings (-mos, -em) are exactly the same as the personal infinitive's — which is why for nós and vocês the form is visibly not the infinitive: se falarmos, se eles comerem. The illusion of "it's just the infinitive" only holds for the singular and the eu form.
Se vocês chegarem cedo, a gente janta antes do filme.
If you all arrive early, we'll have dinner before the movie. — 'chegarem' shows the future subjunctive is conjugated, not an infinitive
Se nós formos de carro, chegamos mais rápido.
If we go by car, we'll get there faster. — 'formos' is the future subjunctive of ir/ser
Irregular future subjunctives
The future subjunctive is built from the third-person plural preterite stem (drop -ram, add the endings), so irregular preterites carry their irregularity here too. These are extremely common and worth memorizing:
| Infinitive | Future subjunctive (eu / ele) | Meaning in a se-clause |
|---|---|---|
| ser / ir | for | se eu for / se ele for |
| ter | tiver | se eu tiver |
| estar | estiver | se você estiver |
| fazer | fizer | se ele fizer |
| poder | puder | se eu puder |
| querer | quiser | se você quiser |
| vir | vier | se ela vier |
| dizer | disser | se eu disser |
| trazer | trouxer | se você trouxer |
Se você puder, me passa o sal.
If you can, pass me the salt. — 'puder', not 'poder'
Se ele fizer isso de novo, eu vou reclamar.
If he does that again, I'm going to complain. — 'fizer', not 'fazer'
What can follow in the main clause
The se-clause sets the condition; the main clause can take several future-leaning forms with no change in basic meaning. Brazilians mix these freely:
| Main-clause form | Example |
|---|---|
| periphrastic future (vou + inf.) | Se der certo, eu vou comemorar. |
| simple present (future sense) | Se der certo, eu comemoro. |
| imperative | Se der certo, me avisa! |
| synthetic future (more formal) | Se der certo, comemorarei. |
Se sobrar comida, leva pra casa.
If there's food left over, take it home. — future subjunctive 'sobrar' + imperative 'leva'
How English does it — and why that misleads you
English uses the present tense in the if-clause to talk about the future: "If it rains tomorrow, I won't go." No special form. Portuguese refuses to do this — it demands the future subjunctive (se chover) precisely because the event is hypothetical and future. So the English structure "if + present → future" maps onto Portuguese "se + future subjunctive → future," and the English present tense is the wrong template.
| English | Brazilian Portuguese |
|---|---|
| If it rains tomorrow, I won't go. | Se chover amanhã, eu não vou. |
| If you want, we'll go together. | Se você quiser, a gente vai junto. |
| If I have time, I'll call you. | Se eu tiver tempo, eu te ligo. |
Common Mistakes
❌ Se chover amanhã, eu não vou à praia. → ❌ Se chove amanhã, eu não vou.
Incorrect for a specific future — the present indicative 'chove' reads as a habit, not tomorrow's forecast.
✅ Se chover amanhã, eu não vou à praia.
If it rains tomorrow, I won't go to the beach. — future subjunctive for the specific future.
❌ Se você quer, a gente vai junto. (planning a future outing)
Incorrect for a future plan — 'quer' (present) means 'if you want [right now, as a fact]'.
✅ Se você quiser, a gente vai junto.
If you want, we'll go together. — future subjunctive 'quiser' for the conditional offer.
❌ Se eu terei tempo, eu te ligo.
Incorrect — the future indicative 'terei' cannot go in the se-clause.
✅ Se eu tiver tempo, eu te ligo.
If I have time, I'll call you. — future subjunctive 'tiver'.
❌ Se nós for de carro, chegamos rápido.
Incorrect — the future subjunctive must agree with 'nós': 'formos', not 'for'.
✅ Se nós formos de carro, chegamos rápido.
If we go by car, we'll get there fast. — correct 'nós' form.
❌ Se ele fazer isso, eu reclamo.
Incorrect — 'fazer' is the infinitive; the future subjunctive of an irregular verb is 'fizer'.
✅ Se ele fizer isso, eu reclamo.
If he does that, I'll complain. — irregular future subjunctive 'fizer'.
Key Takeaways
- Open conditionals are real and possible conditions.
- Habit / general truth → present indicative in both clauses (se chove, eu fico).
- Specific future → future subjunctive in the se-clause + a future form in the main clause (se chover amanhã, eu não vou).
- The future subjunctive looks like the infinitive in the singular but is fully conjugated (se nós formos, se eles chegarem) and inherits irregular preterite stems (tiver, fizer, puder, quiser).
- English uses the present after "if" for the future; Portuguese never does — this is the single most common error English speakers make here.
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Start learning Portuguese→Related Topics
- Contrary-to-Fact Conditionals (Present)B1 — Present hypotheticals in Brazilian Portuguese — se + imperfect subjunctive + conditional (Se eu tivesse dinheiro, compraria), and the colloquial swap of conditional for imperfect indicative (comprava).
- Complex Grammar: OverviewB1 — A map of Brazilian Portuguese's clause-combining machinery — conditionals, reported speech, relative clauses, cleft sentences, and the structures that take you from intermediate to advanced.
- Subjunctive in 'Se' (If) ClausesB1 — The three types of se-clause in Brazilian Portuguese and the mood each one selects — plus the critical difference between se meaning 'if' and se meaning 'whether'.
- Futuro do Subjuntivo: UsageA2 — When to use the future subjunctive in Brazilian Portuguese — the obligatory form after 'quando', 'se', 'enquanto', 'assim que' and other time conjunctions pointing to the future.
- Future Subjunctive vs Future IndicativeB1 — Why 'quando você chegar' (future subjunctive) pairs with a main-clause future like 'eu vou te ligar' — how the two halves of a future sentence each pick their own form.