Portuguese Subjunctive: Doubt, Uncertainty

The subjunctive is like a mood ring. It changes based on the "trigger" word that comes before it. Usually, you have a main clause that expresses doubt. Then, you have the word que (that). Finally, you have the verb in the subjunctive. For example: Duvido (I doubt) + que (that) + ele venha (he comes). Without that first part expressing doubt, the subjunctive usually doesn't show up. It is a team player. It needs a partner to tell it when to act. Even native speakers sometimes skip it in very casual speech. But if you want to sound polished, you need to master this dance.

1. 1Creating these verbs is easier than it looks. It is a simple swap! Follow these steps:
2. 2Start with the eu form of the Present Indicative. For example, falar becomes falo.
3. 3Drop the final -o. Now you have the stem: fal-.
4. 4For -ar verbs, use -e endings. For -er and -ir verbs, use -a endings.
5. 5Here is the pattern for -ar verbs (falar):
6. 6Eu fale
7. 7Tu fales
8. 8Ele/Ela/Você fale
9. 9Nós falemos
10. 10Eles/Elas/Vocês falem
11. 11And for -er verbs (comer):
12. 12Eu coma
13. 13Tu comas
14. 14Ele/Ela/Você coma
15. 15Nós comamos
16. 16Eles/Elas/Vocês comam
17. 17Yes, it feels like the verbs are wearing each other's clothes! -ar verbs take the -e and -er verbs take the -a. It is a little confusing at first, like trying to use a Mac after years on Windows. But you will get used to it quickly.

You need the subjunctive whenever you are not standing on solid ground. Use it after these common triggers:

• Duvidar que (To doubt that): Duvido que ele saiba. (I doubt he knows.)
• Não achar que (To not think that): Não acho que ela venha. (I don't think she's coming.)
• Talvez (Maybe): Talvez nós vamos... Wait! Actually, Talvez is special. It almost always triggers the subjunctive: Talvez nós vamos becomes Talvez nós vamos? No, it's Talvez nós vamos... actually, for ir, it's Talvez nós vamos? No, it's Talvez nós vamos... let's use comer: Talvez nós comamos cedo.
• É possível que (It is possible that): É possível que chova hoje. (It might rain today.)
• Não acreditar que (To not believe that): Não acredito que você diga isso. (I don't believe you're saying that.)

Use it when ordering food if you aren't sure if they have the dish: "Is it possible you have fish?" Use it in job interviews when discussing hypothetical scenarios. It shows you understand that the future is flexible.

Don't use the subjunctive when you are sure. If you say Eu acho que... (I think that...), you usually use the indicative in Brazil. Why? Because you are stating your opinion as a fact of your mind.

• Tenho a certeza que... (I am sure that...) -> Indicative.
• É verdade que... (It is true that...) -> Indicative.
• Acredito que... (I believe that...) -> Indicative.

Think of it like a light switch. Certainty is "On" (Indicative). Doubt is "Off" (Subjunctive). If you use the subjunctive for a fact, you will sound like you are questioning reality. People might think you've had too much coffee!

The biggest mistake is forgetting the "yo" form stem. For example, the verb trazer (to bring) becomes trago in the eu form. So, the subjunctive is traga, not traza.

Another mistake is using the indicative after talvez. In English, we say "Maybe he is here." In Portuguese, saying Talvez ele está aqui sounds a bit "broken" to a native ear. It should be Talvez ele esteja aqui.

Also, watch out for the nós form. Many people forget to change the ending. It is not falamos, it is falemos. It sounds slightly different, but it matters! It's like the difference between "dessert" and "desert." One is much better at a party.

Let's compare two sentences:

1. 1Acho que ele ganha o jogo. (I think he wins the game.) - Indicative. I am confident.
2. 2Não acho que ele ganhe o jogo. (I don't think he wins the game.) - Subjunctive. I am expressing doubt.

Notice how the negative Não flips the switch? In Portuguese, negative opinions almost always trigger the subjunctive because they introduce uncertainty. Positive opinions stay in the indicative because you are asserting your belief. It is a subtle psychological shift that makes the language very expressive.