Forming Future Subjunctive from Pre

The Future Subjunctive is all about hypothetical situations in the future. It usually follows specific triggers that signal a condition or a future timeframe. Unlike the Present Subjunctive, which often deals with emotions or wishes right now, the Future Subjunctive looks ahead. It asks: "What will happen if X occurs?" or "What will we do when Y happens?" It is a dependent tense. This means it rarely stands alone. It needs a main clause to give it context. For example, in the sentence "If I have money, I will buy it," the "If I have" part is where this tense lives. It creates a bridge between a potential condition and a future result. It is like a grammar traffic light. It stays yellow (caution/possibility) until the condition is met, then the main action turns green. Even native speakers occasionally slip up with irregular forms, so you are in good company. Just remember: if there is a "maybe" in the future, the Future Subjunctive is likely there too.

1. 1To form this tense, you need a secret weapon: the Preterite. Specifically, the third-person plural (eles/elas) of the Preterite Indicative. This is the most reliable way to find the correct stem, especially for irregular verbs. Follow these three simple steps:
2. 2Start with the eles form of the Preterite (Past). For example, falaram (they spoke) or tiveram (they had).
3. 3Remove the -am ending. This leaves you with the stem: falar- or tiver-.
4. 4Add the Future Subjunctive endings to that stem.
5. 5The endings are the same for all verb groups (-ar, -er, -ir):
6. 6Eu: -r (falar / tiver)
7. 7Tu: -res (falares / tiveres)
8. 8Ele/Ela/Você: -r (falar / tiver)
9. 9Nós: -rmos (falarmos / tivermos)
10. 10Vós: -rdes (falardes / tiverdes)
11. 11Eles/Elas/Vocês: -rem (falarem / tiverem)
12. 12For regular verbs, the result looks exactly like the Personal Infinitive. This is a lucky break for your memory! However, for irregular verbs like ter (to have), fazer (to do), or ir (to go), the stem change is vital. Fizeram becomes fizer, and vieram becomes vier. If you skip the Preterite step, you might end up saying something like "se eu fazer," which sounds a bit like saying "if I be" in English. Stick to the "Preterite Trick" and you will be golden.

You will use this tense primarily after certain conjunctions. The most common ones are se (if) and quando (when). Imagine you are ordering food and you say, "If the food is good, I will come back." In Portuguese, that "is" must be in the Future Subjunctive: Se a comida for boa... Here are the main scenarios:

• Conditions with se: When something depends on a future possibility. "If you want (se você quiser), we can go."
• Future time with quando: When an action will happen at an unspecified time. "When I arrive (quando eu chegar), I'll call you."
• Relative clauses: After words like quem (whoever) or o que (whatever) when the person or thing is unknown. "Whoever wins (quem ganhar) gets a prize."
• Temporal markers: Words like assim que (as soon as), logo que (as soon as), or enquanto (while/as long as). "As soon as they finish (assim que eles terminarem), they will leave."

Think of it as the tense for "The Great Unknown." It is perfect for job interviews: "When I start working here..." (Quando eu começar...). It is also great for travel: "If I have time..." (Se eu tiver tempo...).

It is easy to get "subjunctive happy" and use it everywhere, but be careful. Do not use it for certainties or habitual actions in the present. If you say "When I arrive home, I always eat," you use the Present Indicative (quando chego) because it is a habit. The Future Subjunctive is only for that specific, one-off future "maybe." Also, do not use it after que when expressing wishes or emotions; that is the territory of the Present Subjunctive. For example, "I hope that you go" uses que você vá (Present Subjunctive), not the future form. Finally, avoid using it after se if you are talking about a past impossibility (that is the Imperfect Subjunctive). If you find yourself using it for things that are definitely happening right now, hit the brakes! It is strictly for the "not yet" and the "might be."

The biggest trap is the ver (to see) vs. vir (to come) confusion. This is the ultimate test for C1 learners. The Future Subjunctive of ver is vir (from viram). The Future Subjunctive of vir is vier (from vieram). If you say se eu ver, you are actually saying "if I come" in a very broken way. Another common slip is using the present tense after se. English speakers often say "If I go," but in Portuguese, "If I will go" logic applies: Se eu for. Also, watch out for the verb ter. Many people say se eu ter, but the correct form is se eu tiver. Think of it like a grammar pothole; if you know where it is, you can drive right around it. Lastly, don't forget to conjugate the nós and eles forms. Using the singular for everyone makes your Portuguese sound a bit flat.

You might confuse this with the Personal Infinitive. For regular verbs, they look identical. However, the Personal Infinitive is used after prepositions (like para or sem), while the Future Subjunctive is used after conjunctions (like se or quando).

Compare:

• Para eles falarem (In order for them to speak) - Personal Infinitive.
• Quando eles falarem (When they speak) - Future Subjunctive.

Another contrast is with the Present Subjunctive. Use the Present Subjunctive for desires, doubts, or emotions *now*. Use the Future Subjunctive for conditions that might happen *later*.

• Duvido que ele venha (I doubt he is coming/will come - Present Subjunctive).
• Se ele vier, avisarei (If he comes, I will let you know - Future Subjunctive).