The Portuguese Future Subjunctive: Use Se and Quando Naturally
After se or quando refers to an uncertain future event, Brazilian Portuguese often uses a future subjunctive form: quando eu chegar.
Real Life Portuguese · 6 min read · Updated October 14, 2026
The short answer
When se, quando, assim que, or enquanto introduces a future event that is not yet certain or complete, Brazilian Portuguese commonly uses the future subjunctive. The sentence may describe what will happen if a condition is met or when an event occurs: se você precisar, me chama (if you need anything, call me).
Recognize the future subjunctive after time and condition words
The future subjunctive often looks like the personal infinitive for regular verbs, but common irregular verbs have forms worth learning: quando eu tiver (when I have), se ela fizer (if she does), assim que eles forem (as soon as they go/are).
Quando eu chegar, mando uma mensagem.
When I arrive, I’ll send a message.
Se você quiser, a gente pede comida.
If you want, we can order food.
Assim que eles souberem, vão contar para nós.
As soon as they know, they’ll tell us.
Do not use the present subjunctive for every future clause
English uses a present form after ‘when’ in a future sentence (‘when I arrive’), but Portuguese often changes the verb: quando eu chegar. The future subjunctive is especially useful after these conjunctions when the clause points to a future possibility. If the event is habitual or already established, the present tense may be right instead: quando chego cedo, tomo café em casa (when I arrive early, I have coffee at home).
This pattern is related to forms such as se eu for, the future of ir and ser. Learn it through complete time and condition clauses rather than translating each English verb ending in isolation.
Se chover amanhã, vamos ficar em casa.
If it rains tomorrow, we’ll stay home.
Quando você tiver um minuto, pode me ligar?
When you have a minute, could you call me?
Se eu fizer a reserva, você escolhe o horário?
If I make the reservation, will you choose the time?
Put it into practice
After se, quando, assim que, or enquanto points to an uncertain future event, look for the future subjunctive: se chover, quando eu chegar, assim que você puder.
Quick practice
Which Portuguese example matches “If it rains tomorrow, we’ll stay home”?
Choose an answer to check yourself.
Keep practicing with the Real Life Portuguese app
Build on this guide with everyday expressions and native Brazilian audio. Choose iPhone, Android, or the web app.