Future Subjunctive in Portuguese

In Brief

Portuguese normally uses the future subjunctive in a dependent clause about a possible or not-yet-completed future event: Se tiver tempo, vou (“If I have time, I’ll go”) and Quando chegares, telefona-me (“When you arrive, call me”). Form it from the third-person plural of the pretérito perfeito: remove final -am from falaram, fizeram, tiveram to get falar, fizer, tiver, then add the personal endings.

Overview

The future subjunctive (conjuntivo futuro in European Portuguese and also subjuntivo futuro in Brazilian terminology) is a mood, meaning a verb form that shows how the speaker presents an event rather than simply when it occurs. Here, the event belongs to the future but is still conditional, pending, or unidentified: you do not yet know whether someone will have time, when a visitor will arrive, or who will finish first.

English usually uses a present-tense form in the same situation: “when you arrive” or “if she can.” Portuguese marks the future relationship on the verb in the dependent clause: quando chegares, se ela puder. That mismatch makes this B2 pattern easy to understand but easy to forget.

This form builds on the present subjunctive, but the two do different jobs. The present subjunctive commonly follows wishes, judgments, commands, and doubts (Espero que venhas); the future subjunctive commonly follows connectors such as se and quando when their clause points forward (Se vieres amanhã...).

How It Works

Build the stem from the completed past

Take the third-person plural (“they”) form of the pretérito perfeito—the simple completed past—and remove -am:

Infinitive	“They” in the completed past	Remove -am	Future subjunctive stem
falar	falaram	falar-	falar
comer	comeram	comer-	comer
partir	partiram	partir-	partir
fazer	fizeram	fizer-	fizer
ter	tiveram	tiver-	tiver
vir	vieram	vier-	vier

This rule is more reliable than starting with the infinitive. Regular stems happen to look like the infinitive, but irregular verbs preserve the special past stem: fazer → fizeram → fizer, not fazer; poder → puderam → puder, not poder.

Add the personal endings

The endings are the same for all verb classes. The first- and third-person singular have no added ending.

Person	Ending	falar	comer	partir
eu	—	falar	comer	partir
tu	-es	falares	comeres	partires
ele/ela/você	—	falar	comer	partir
nós	-mos	falarmos	comermos	partirmos
vós	-des	falardes	comerdes	partirdes
eles/elas/vocês	-em	falarem	comerem	partirem

In everyday Brazilian Portuguese, vós is rare; vocês takes the third-person plural. In Portugal, vocês also takes third-person plural, while vós survives in limited regional, religious, or formal settings.

Learn the high-frequency irregular stems

Infinitive	Future subjunctive	Sample form
ser / ir	for-	quando eu for
estar	estiver-	se estiveres
ter	tiver-	quando tivermos
vir	vier-	se vierem
poder	puder-	assim que puder
fazer	fizer-	quando fizeres
dizer	disser-	se disserem
querer	quiser-	se quiser
saber	souber-	quando soubermos
dar	der-	se der tempo
trazer	trouxer-	quando trouxeres

Ser (“to be”) and ir (“to go”) both use forms such as for, fores, formos, and forem. Context supplies the meaning: quando for médico means “when he becomes/is a doctor,” while quando for ao Porto means “when he goes to Porto.”

The main environments

Use the form when a future event appears after:

• se (“if”): Se chover, ficamos em casa.
• quando (“when”): Quando acabares, avisa-me.
• enquanto (“while” or “as long as”): Enquanto viveres aqui, tens a chave.
• assim que / logo que (“as soon as”): Assim que souber, telefono.
• depois que (“after,” especially common in Brazil): Depois que terminares, conversamos.
• relative expressions with an unknown future person or thing: Quem chegar primeiro abre a porta; Escolhe o que quiseres.

The future meaning is essential. For routines and facts, use the indicative (the ordinary fact-stating mood): Quando chego a casa, tiro os sapatos (“When I get home, I take off my shoes”). For a specific arrival that has not happened yet: Quando chegar a casa, telefono-te (“When I get home, I’ll call you”).

Keep the two clauses separate

The connector introduces the condition or time clause; the result clause chooses whatever form its meaning requires:

• future subjunctive + future or present with future value: Se puder, vou/irei.
• future subjunctive + command: Quando chegares, liga-me.
• future subjunctive + modal expression: Quem terminar pode sair.

Portuguese often uses the present indicative in the result clause for a natural conversational future (vou, faço, telefono). That does not change the future subjunctive in the dependent clause.

Examples in Context

Portuguese	English	Note
Quando chegares, telefona-me.	When you arrive, call me.	A future arrival followed by a command.
Se tiver tempo, irei.	If I have time, I’ll go.	Ter uses the irregular stem tiver-.
Enquanto viveres, terás sempre algo para aprender.	As long as you live, you will always have something to learn.	Enquanto means “as long as” here.
Assim que puder, farei isso.	As soon as I can, I’ll do that.	The ability is pending; puder is not poder.
Se chover amanhã, cancelamos o piquenique.	If it rains tomorrow, we’ll cancel the picnic.	The present cancelamos has future meaning.
Quando soubermos o resultado, avisamos toda a gente.	When we know the result, we’ll tell everyone.	First-person plural of saber: soubermos.
Se vocês quiserem, podemos começar mais cedo.	If you want, we can start earlier.	Vocês requires quiserem.
Logo que ele vier, servimos o jantar.	As soon as he comes, we’ll serve dinner.	Vir → vier, often confused with ver → vir.
Quem terminar primeiro pode sair.	Whoever finishes first may leave.	The future person is not yet known.
Leva o casaco que quiseres.	Take whichever coat you want.	The choice has not yet been made.
Se der tempo, passo pelo supermercado.	If there is enough time, I’ll stop by the supermarket.	Common impersonal use of dar.
Quando formos a Lisboa, visitaremos o museu.	When we go to Lisbon, we’ll visit the museum.	Formos comes from ir here.
Se disseres a verdade, será mais fácil ajudar-te.	If you tell the truth, it will be easier to help you.	Irregular dizer → disser-.
Enquanto estiverem no hotel, podem usar a piscina.	While you are staying at the hotel, you may use the pool.	A bounded future stay.

Common Mistakes

Copying the English present tense

• Wrong: Quando chegas amanhã, telefona-me.
• Right: Quando chegares amanhã, telefona-me.
• Why: English says “when you arrive,” but a not-yet-real future arrival normally requires the future subjunctive in Portuguese.

Building an irregular form from the infinitive

• Wrong: Se poder, vou contigo.
• Right: Se puder, vou contigo.
• Why: Use the third-person plural completed past: puderam minus -am gives puder.

Using it for a repeated routine

• Wrong: Quando chegar ao trabalho, tomo café. (if you mean “every day”)
• Right: Quando chego ao trabalho, tomo café.
• Why: A regular habit is presented as a fact, so it takes the indicative. Quando chegar instead refers to a particular future arrival.

Using the present subjunctive after future se

• Wrong: Se tenha tempo, ajudo-te.
• Right: Se tiver tempo, ajudo-te.
• Why: A possible future condition after se takes tiver. Present-subjunctive tenha belongs in patterns such as Espero que tenha tempo (“I hope you have time”).

Confusing vier and vir

• Wrong: Se ele vir amanhã, falamos. (meaning “if he comes”)
• Right: Se ele vier amanhã, falamos.
• Why: Vier is from vir (“come”). Vir can be the future subjunctive of ver (“see”): Se ele vir o aviso... means “If he sees the notice...”

Usage Notes

Both European and Brazilian Portuguese use the future subjunctive actively; it is not merely literary. The name differs by tradition: conjuntivo is usual in Portugal, while subjuntivo is usual in Brazil. The grammar itself is shared, although vocabulary, pronouns, and preferred future forms vary.

In conversation, the main clause often has a present form with future meaning: Se puder, vou rather than the more formal-sounding Se puder, irei. European Portuguese may use an imperative and attached object pronoun (telefona-me, avisa-me); Brazilian speech is more likely to use alternatives such as me liga or me avisa. These are register and regional choices, not changes to the subjunctive rule.

Do not treat every word meaning “when” as an automatic trigger. Time reference controls the choice: quando posso can describe what is generally true (“when I can”), whereas quando puder points to a future opportunity (“when I can next do it”).

Beyond the Basics / Advanced Use

Unknown future referents

The form is not limited to explicit time and condition clauses. A relative clause—a clause describing a person or thing—can use it when that person or thing has not yet been identified:

• Contrataremos quem tiver mais experiência. — “We’ll hire whoever has the most experience.”
• Podes escolher o livro que quiseres. — “You can choose whichever book you want.”
• Haverá um prémio para quem resolver o problema. — “There will be a prize for whoever solves the problem.”

The speaker is not asserting a fact about a known person. The identity will be settled later, which makes the future subjunctive natural.

Future subjunctive versus personal infinitive

For regular verbs, several forms look exactly like the personal infinitive (an infinitive with endings that identify its subject): falarmos, comerem. Meaning and sentence structure distinguish them.

Future subjunctive	Personal infinitive
Se fizermos isso, será melhor. — If we do that, it will be better.	É melhor fazermos isso. — It is better for us to do that.
Quando tiverem tempo, liguem. — When you have time, call.	Antes de terem tempo para responder... — Before they have time to answer...

Irregular verbs make the contrast visible: future subjunctive fizermos, tiverem versus personal infinitive fazermos, terem. A connector such as se or future quando strongly points to the future subjunctive; a preposition such as para, antes de, or por often introduces an infinitive construction.

Conditions about other times

Future se clauses use the future subjunctive: Se tiver dinheiro amanhã, compro o bilhete. A hypothetical condition about the present or future usually uses the imperfect subjunctive plus conditional: Se tivesse dinheiro, compraria o bilhete (“If I had money, I would buy the ticket”). An unreal condition in the past needs past forms: Se tivesse tido dinheiro, teria comprado o bilhete. Choosing among these patterns shows whether the condition is open, remote, or already impossible.

Practice Tips

1. Use the past-form shortcut. Write ten common third-person plural past forms—foram, fizeram, tiveram, puderam, vieram—cross out -am, and then add -es, -mos, and -em. This trains the irregular stems as a system rather than as isolated words.
2. Make three-way contrasts. For each verb, write a routine, an open future event, and a hypothetical event: Quando tenho tempo... / Quando tiver tempo... / Se tivesse tempo.... Saying what changes in meaning is more useful than reciting endings alone.
3. Listen for connectors. In Portuguese audio, note every se, quando, assim que, and quem. Decide whether the clause is factual, future and open, or hypothetical before checking the verb form.

Related Concepts

• Prerequisite: Present Subjunctive — introduces the subjunctive as a mood and provides a useful contrast with future conditions and time clauses.