The little word se does a lot of work in Brazilian Portuguese, and it controls some of the trickiest mood choices in the language. The headache for English speakers is that English uses "if" for two completely different things — real conditions ("if it rains, I'll stay home") and reported uncertainty ("I don't know if it'll rain") — and lets the verb sit in the present tense for both. Portuguese splits these apart: conditional se triggers the future subjunctive for hypothetical futures, while se meaning "whether" stays firmly in the indicative. This page maps the three types of conditional se-clause and then isolates the "if vs whether" trap.
The thread tying everything together is the same one that runs through the whole subjunctive: real, asserted events take the indicative; events held up as hypothetical, counterfactual, or merely reported take the subjunctive or the conditional.
Type 1 — Real / open conditions (likely or habitual)
When the condition is realistic and the consequence follows naturally, you have a real conditional. Brazilian Portuguese offers two patterns:
- Habitual / general truth: se
- Specific future: se
- future subjunctive, with a present or future result. This describes one anticipated future scenario.
Se chove, a rua aqui alaga na hora.
If (whenever) it rains, the street here floods immediately. (habitual — present indicative: chove)
Se chover amanhã, eu fico em casa.
If it rains tomorrow, I'll stay home. (specific future — future subjunctive: chover)
This is the crucial pair: chove (habitual indicative) vs chover (future subjunctive for a single anticipated event). English uses "if it rains" for both. Portuguese, like with quando, reserves the future subjunctive for the not-yet-real future event.
Se você vier à festa, leva um vinho.
If you come to the party, bring some wine. (future subjunctive: vier, not 'vem')
Type 2 — Hypothetical / contrary-to-fact (present)
When the condition is unlikely, imaginary, or contrary to the present facts ("if I had money — but I don't"), the structure is se + imperfect subjunctive, with the result in the conditional.
Se eu tivesse dinheiro, compraria uma casa na praia.
If I had money, I'd buy a beach house. (but I don't — imperfect subjunctive 'tivesse' + conditional 'compraria')
Se eu fosse você, não aceitaria essa proposta.
If I were you, I wouldn't accept that offer. (fosse + aceitaria)
The imperfect subjunctive is built from the eles preterite minus -ram, plus the endings -sse etc.: tiveram → tivesse, foram → fosse, fizeram → fizesse. In everyday speech, Brazilians very commonly replace the conditional in the result clause with the imperfect indicative — Se eu tivesse dinheiro, comprava uma casa — which is fully natural and even dominant in casual conversation, though the conditional (compraria) is preferred in writing.
Se ele estudasse mais, passaria de ano sem dificuldade.
If he studied more, he'd pass the year easily. (estudasse + passaria)
Type 3 — Counterfactual past
For something that could have happened but didn't, you move both halves into the past: se + pluperfect subjunctive (mais-que-perfeito do subjuntivo: tivesse/houvesse + past participle), with the result in the conditional composto (teria + past participle).
Se eu tivesse sabido, teria avisado você na mesma hora.
If I had known, I would have warned you right away. (tivesse sabido + teria avisado)
Se eles tivessem saído mais cedo, não teriam perdido o voo.
If they had left earlier, they wouldn't have missed the flight.
This maps neatly onto English's "if I had known, I would have told you" — the third conditional. The mechanics differ (Portuguese builds the protasis with the pluperfect subjunctive tivesse + particípio), but the meaning lines up cleanly, which makes Type 3 one of the more learnable patterns once Type 2 is solid.
| Type | Se-clause | Result clause | Meaning |
|---|---|---|---|
| 1 (habitual) | present indicative — se chove | present indicative — alaga | general truth |
| 1 (future) | future subjunctive — se chover | present/future — fico / vou ficar | likely future |
| 2 (present hypothetical) | imperfect subjunctive — se tivesse | conditional — compraria | contrary to present fact |
| 3 (past counterfactual) | pluperfect subjunctive — se tivesse sabido | conditional composto — teria avisado | contrary to past fact |
The critical split: se = "if" vs se = "whether"
This is where English transfer does the most damage. The same word se introduces two grammatically opposite structures:
- Conditional se ("if") — sets up a hypothesis. Triggers the future subjunctive (Type 1 future) or the imperfect/pluperfect subjunctive (Types 2 and 3).
- Interrogative se ("whether") — reports an indirect yes/no question. Takes the indicative, never the subjunctive.
Não sei se ele vem amanhã.
I don't know whether he's coming tomorrow. ('whether' — indicative: vem)
Se ele vier amanhã, a gente conversa.
If he comes tomorrow, we'll talk. ('if' — future subjunctive: vier)
Same verb (vir), same adverb (amanhã), opposite mood — and the only difference is whether se means "whether" or "if." The "whether" se answers a yes/no question buried inside the sentence (Ele vem? — Não sei), so the embedded clause keeps the indicative it would have as a standalone question. The "if" se sets up a hypothesis, so it triggers the subjunctive.
Ela perguntou se eu estava bem.
She asked whether I was okay. (reported question — indicative: estava)
Me avisa se você precisar de alguma coisa.
Let me know if you need anything. (conditional 'if' — future subjunctive: precisar)
Common Mistakes
❌ Se chover amanhã, eu ficava em casa.
Incorrect — a real future condition pairs with the present/future, not the imperfect: 'fico'
✅ Se chover amanhã, eu fico em casa.
If it rains tomorrow, I'll stay home.
❌ Se eu tinha dinheiro, comprava uma casa.
Incorrect — a present hypothetical needs the imperfect subjunctive 'tivesse'
✅ Se eu tivesse dinheiro, comprava uma casa.
If I had money, I'd buy a house.
❌ Não sei se ele venha amanhã.
Incorrect — 'whether' takes the indicative, not the subjunctive: 'vem'
✅ Não sei se ele vem amanhã.
I don't know whether he's coming tomorrow.
❌ Se você vem à festa, leva um vinho.
Incorrect — a future condition needs the future subjunctive 'vier'
✅ Se você vier à festa, leva um vinho.
If you come to the party, bring some wine.
❌ Se eu soubesse, eu avisava você. (for a finished past event)
Incomplete for a past counterfactual — use the pluperfect subjunctive + conditional composto
✅ Se eu tivesse sabido, teria avisado você.
If I had known, I would have warned you.
Key Takeaways
- Real future "if" → future subjunctive (se chover), result in present/future.
- Present hypothetical "if" → imperfect subjunctive + conditional (se tivesse... compraria); colloquially the result can be imperfect indicative (comprava).
- Past counterfactual "if" → pluperfect subjunctive + conditional composto (se tivesse sabido... teria avisado).
- se = "if" triggers the subjunctive; se = "whether" stays indicative (não sei se ele vem). The "whether" test settles it.
- Only a small club of conjunctions take the future subjunctive: se, quando, enquanto, assim que, logo que, sempre que.
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Start learning Portuguese→Related Topics
- Conjunctions of Time + SubjunctiveB1 — Temporal conjunctions like quando, assim que and antes que that govern the future subjunctive for future events — and the outlier antes que, which always takes the subjunctive.
- Subjunctive vs Indicative: Side-by-SideB1 — Minimal pairs where switching between the subjunctive and the indicative changes the meaning of the sentence, not just its register.
- 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.
- Conditional for Hypothetical SituationsB1 — Using the conditional in 'if...would' sentences, plus the colloquial Brazilian habit of replacing it with the imperfect indicative.