A conditional sentence says: if this, then that. In Brazilian Portuguese the word for "if" is se, and the whole system turns on one question — how real or unreal is the condition? An open possibility ("If it rains, I'll stay home"), a present-day hypothesis ("If I had the money, I'd buy it"), and a regret about the past ("If I'd known, I'd have warned you") each demand a different pairing of tenses. Choose the wrong pairing and a Brazilian will understand you, but you'll sound like you're guessing.
This page is a map, not the full territory. It gives you the three time-frames at a glance, shows the tense pairing for each, and points you to the detailed pages for the deep work. Think of it as the table of contents for conditionals.
The three time-frames
Every se-conditional fits into one of three frames. The key is to identify how likely the condition is, and when it sits in time.
| Type | Meaning | If-clause (with "se") | Main clause |
|---|---|---|---|
| genuinely possible | future subjunctive | present or future |
| unlikely / imagined now | imperfect subjunctive | conditional (futuro do pretérito) |
| impossible — didn't happen | pluperfect subjunctive | conditional perfect |
The single most important thing to absorb is that the se-clause almost always takes the subjunctive (future, imperfect, or pluperfect), while the main clause takes an indicative or conditional tense. This split — subjunctive in the condition, indicative/conditional in the result — is the backbone of the entire system.
Type 1: Real / open conditions
These are conditions that genuinely might happen. English uses the present tense in the if-clause ("If it rains..."), but here is a famous Brazilian trap: Portuguese uses the future subjunctive in the se-clause, a tense English doesn't have at all.
Se chover, eu fico em casa.
If it rains, I'll stay home.
Se você quiser, a gente vai junto.
If you want, we'll go together.
Se eu tiver tempo amanhã, te ligo.
If I have time tomorrow, I'll call you.
Look at the se-clause verbs: chover, quiser, tiver — these are future subjunctive forms, not present indicative. English "If it rains" maps to Se chover, never Se chove. This is the error English speakers make most, because their own grammar tells them to use a present-like form. The detailed mechanics live on the open conditions page.
Type 2: Hypothetical (present / unreal now)
These imagine a situation that isn't true right now — a daydream, a piece of advice, a polite hypothetical. The se-clause uses the imperfect subjunctive, and the main clause uses the conditional (in Brazil also called the futuro do pretérito, the form ending in -ria).
Se eu tivesse dinheiro, eu compraria aquele apartamento.
If I had money, I'd buy that apartment.
Se eu fosse você, eu não faria isso.
If I were you, I wouldn't do that.
Se a gente morasse na praia, eu surfaria todo dia.
If we lived at the beach, I'd surf every day.
Note the pairing: tivesse + compraria, fosse + faria, morasse + surfaria. The imperfect subjunctive (-sse) signals "this isn't real"; the conditional (-ria) carries the imagined result. This matches English "If I had... I would..." almost one-to-one, which makes it the most intuitive frame for English speakers. The full treatment is on the contrary-to-fact page.
Type 3: Counterfactual (past / what might have been)
These look back at something that didn't happen and imagine the alternative — regrets, recriminations, relief. The se-clause uses the pluperfect subjunctive (tivesse + past participle) and the main clause the conditional perfect (teria + past participle).
Se eu tivesse sabido, eu teria avisado você.
If I had known, I would have warned you.
Se a gente tivesse saído mais cedo, não teria perdido o voo.
If we had left earlier, we wouldn't have missed the flight.
Se você tivesse estudado, teria passado na prova.
If you had studied, you would have passed the exam.
This is the most morphologically heavy frame — two compound forms — but it lines up cleanly with English "If I had known, I would have warned you." The past counterfactual page drills the forms.
Conditionals without "se"
Not every conditional uses se. Several conjunctions express conditions with their own nuance, and most of them require the subjunctive in their clause.
| Connector | Meaning | Mood |
|---|---|---|
| caso | in case / if (slightly more formal than "se") | subjunctive |
| a menos que | unless | subjunctive |
| a não ser que | unless (everyday) | subjunctive |
| desde que | provided that / as long as | subjunctive |
| contanto que | as long as / provided that | subjunctive |
Caso você precise de mim, é só ligar.
In case you need me, just call.
A gente vai à praia amanhã, a menos que chova.
We're going to the beach tomorrow, unless it rains.
Você pode ficar, desde que ajude na limpeza.
You can stay, as long as you help with the cleaning.
Notice caso takes the present subjunctive (precise), not the future subjunctive that se would take (Se você precisar...). That's a clean dividing line: se → future subjunctive for open conditions; caso → present subjunctive. The non-se family is detailed on the conditionals without "se" page.
Common Mistakes
❌ Se chove amanhã, eu fico em casa.
Incorrect — open conditions about the future need the future subjunctive, not present indicative.
✅ Se chover amanhã, eu fico em casa.
If it rains tomorrow, I'll stay home.
❌ Se eu teria dinheiro, eu compraria a casa.
Incorrect — never put the conditional in the 'se'-clause; use the imperfect subjunctive.
✅ Se eu tivesse dinheiro, eu compraria a casa.
If I had money, I'd buy the house.
❌ Se eu sabia, eu teria avisado.
Incorrect — past counterfactual needs the pluperfect subjunctive 'tivesse sabido'.
✅ Se eu tivesse sabido, eu teria avisado.
If I had known, I would have warned you.
❌ Caso você precisar de mim, é só ligar.
Incorrect — 'caso' takes the present subjunctive, not the future subjunctive.
✅ Caso você precise de mim, é só ligar.
In case you need me, just call.
❌ A menos que você vem, a festa não acontece.
Incorrect — 'a menos que' requires the subjunctive 'venha'.
✅ A menos que você venha, a festa não acontece.
Unless you come, the party won't happen.
Key Takeaways
- Conditionals come in three frames: real/open (future subjunctive + present/future), hypothetical-present (imperfect subjunctive + conditional), counterfactual-past (pluperfect subjunctive + conditional perfect).
- The se-clause almost always carries the subjunctive; the main clause carries indicative or conditional. Never put a -ria conditional in the se-clause.
- The biggest English-speaker trap is Type 1: "If it rains" is Se chover (future subjunctive), not Se chove.
- Non-se connectors — caso, a menos que, a não ser que, desde que, contanto que — all trigger the subjunctive; caso specifically takes the present subjunctive.
- This page is the map; follow the cross-references to the detailed si-clause pages for full conjugations and edge cases.
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Start learning Portuguese→Related Topics
- Open Conditionals (Real If-Clauses)A2 — Real, possible if-clauses in Brazilian Portuguese — present indicative for habits and the obligatory future subjunctive (se chover) for specific future conditions.
- 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).
- Past Counterfactual ConditionalsB1 — How to talk about unreal past situations in Brazilian Portuguese — 'if X had happened, Y would have happened' — using the pluperfect subjunctive and the conditional composto.
- Conditionals Without 'Se' (Caso, Desde que, A menos que)B2 — Beyond 'se' — the conditional conjunctions caso, desde que, a menos que, contanto que, and sem que, all of which trigger the subjunctive, plus the gerund as a compact conditional.
- 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'.