Future Subjunctive

As previously mentioned, the futuro do conjuntivofuture subjunctive allows us to talk about the conditions that must be met in order for a potential future action to occur, (i.e. “If this goes well, I will do that” or “When we get home, I will do that”). This tense appears in subordinate adverbial clauses (i.e. clauses which function like an adverb), as well as in relative clauses. It often goes along with the conjunction seif Slow audio Play audio Conjunction or others such as:

• assim queas soon as, once Slow audio Play audio
• sempre quewhenever Slow audio Play audio
• quandowhen Slow audio Play audio Adverb
• enquantowhile, as long as Slow audio Play audio Conjunction
• comohow Slow audio Play audio Adverb
• o quewhat Slow audio Play audio Pronoun

Verb Conjugation

Regular Verbs
With regular verbs, the futuro do conjuntivo is conjugated exactly the same as the infinitivo pessoal (personal infinitive). All you need to do is add the correct terminations to the infinitive, without removing any letters. Both the 1st and 3rd person singular stay exactly the same as the infinitive itself, making the endings as follows: (none), –es, (none), –mos, –em.
Here’s an example of how to conjugate the regular verbs comerto eat Slow audio Play audio Verb and falarto speak Slow audio Play audio Verb :

Irregular verbs
Regarding irregular verbs, you might find the following shortcut useful: Conjugate the verb in the 3rd person plural of the pretérito perfeito (simple past tense), remove the -am ending, then add the same endings shown above, according to each subject: (none), -es, (none), -mos, -em.
Let’s try it out with the irregular verb ser:

1. Conjugate the verb in the 3rd person plural simple past tense: foram
2. Drop the -am ending: for-
3. Now, make it hypothetical! To put it in the futuro do conjuntivo, add the conjunction (such as se) and add the correct ending depending on who we’re talking about:

se eu forif I go
se tu foresif you go
se ela forif she goes
se nós formosif we go
se eles foremif they go

More Examples

Se levares o carro, tens de pôr gasolinaIf you take the car, you have to put gas in it
Assim que chegarem, avisemAs soon as you (pl.) arrive, let me know
Enquanto for estudante, tenho descontoAs long as I'm a student, I get a discount
Faz como quiseresDo it however you want
Quando tiver fome, faço o almoçoOnce I'm hungry, I'll make lunch

Futuro do Conjuntivo vs. Imperfeito do Conjuntivo

You will probably come across a lot of “if” statements in both the imperfeito do conjuntivo and the futuro do conjuntivo, since both can be used to talk about potential future actions. So how do you know when to use which tense?
The difference is that the imperfeito version typically goes along with “if” when talking about a completely hypothetical situation, i.e. something that is unrealistic or unlikely to take place / to have taken place. The futuro version, on the other hand, is usually used along with “if” to talk about a likely or inevitable outcome.
Se eu for passear, vais comigo?If I go for a walk, will you go with me? (futuro do conjuntivo)
Se eu fosse passear, ias comigo?If I went for a walk, would you go with me? (imperfeito do conjuntivo)
While they’re both hypothetical, in the first example, the subject is seriously thinking about going for a walk in the near future. In the second example, the speaker may want to know how the listener feels about walks in general, his company, and/or if they’d join him on a walk some (unspecified) day.

Futuro do Conjuntivo vs. Infinitivo Pessoal

Many (but not all!) irregular verbs are going to have a different conjugation in the infinitivo pessoal (personal infinitive) and the futuro do conjuntivo. However, as we said earlier, regular verbs share the same conjugation in both tenses. So how can you tell the difference between the two? As usual, context is key! Remember that the futuro do conjuntivo is generally used to talk about the conditions that need to be met for a likely outcome to occur.

Conjunction + Futuro do Conjuntivo

As such, the conjunctions used in the sentence can sometimes give you a clue. The futuro do conjuntivo must be preceded by a conjunction, whereas the infinitivo pessoal does not (necessarily) have to. For example:

• Infinitivo pessoal: É melhor vocês porem a mesaIt's better you (pl.) set the table, You (pl.) had better set the table

To say something similar in the futuro do conjuntivo, we could use the conjunction seif Slow audio Play audio Conjunction , which results in a slightly different meaning:

• Futuro do conjuntivo: É melhor se forem vocês a pôr a mesaIt's better if you were the ones to set the table

In the first example, the focus is on you (pl.) doing the action, i.e. commenting that this is something you should do. In the second example, it’s about commenting on the hypothetical possibility of you (pl.) being the ones to do the action, as opposed to someone else doing it. Thus, you can see how they are similar, but the second makes the meaning more conditional.

Para + Infinitivo Pessoal

While we’re on the subject, let’s talk about when the personal infinitive can be preceded by a conjunction. While the future subjunctive appears in adverbial and relative clauses, the personal infinitive appears in substantive ones, preceded by the conjunction para and with verbs that indicate an order. Let’s try it with the regular verb começar:

• Infinitivo pessoal: Ele disse para começares a comerHe told you to start eating, He said for you to start eating

To use the same verb in the future subjunctive, the conjugation is the same. However, notice that we needed to make a few changes, and even added another clause to the sentence. This way we are discussing a potential outcome based on the condition that “you start eating”:

• Futuro do conjuntivo: Ele disse que, se começares a comer, fala contigoHe said that if you start eating, he'll talk to you.