Presente do Conjunt

This mood usually needs a "trigger" word. It rarely stands alone in a sentence. Think of it like a chemical reaction. You need a main clause first. Then you usually need the word que. After that, the magic happens. The second verb changes its form. It moves from reality to possibility. It is like a bridge between two ideas. The first part expresses a wish or doubt. The second part uses the subjunctive. It is a very logical system once you see it. You are signaling to the listener. You are saying "this might not be true."

1. 1Start with the eu form of the present indicative.
2. 2For example, use falo for the verb falar.
3. 3Remove the final -o from the word.
4. 4This gives you the radical fal-.
5. 5Now, swap the thematic vowels.
6. 6For -ar verbs, use the vowel -e.
7. 7For -er and -ir verbs, use the vowel -a.
8. 8Add the standard endings to this new vowel.
9. 9The endings are: -, -s, -, -mos, -is, -m.
10. 10Remember that eu and ele/ela forms are identical.
11. 11Watch out for irregulars like seja or tenha.
12. 12These irregulars usually follow the eu form radical too.
13. 13If eu is irregular, the subjunctive is usually irregular.

Use it for wishes and desires. Say Quero que venhas when inviting a friend. Use it for emotions. Say Fico feliz que estejas aqui at a party. It is essential for doubts. Say Duvido que ele saiba during a mystery. Use it for impersonal expressions. Say É importante que estudes before an exam. It works for requests too. Say Peço que fales baixo in a library. Use it after talvez for uncertainty. Say Talvez ele chegue tarde when waiting for someone. Use it for future possibilities with quando. Say Quando tenhas tempo, liga-me for a favor. It is perfect for job interviews. Say Espero que a empresa cresça to impress them. Use it when ordering food too. Say Quero que a carne esteja mal passada.

Do not use it for facts. Do not use it for certainties. If you are 100% sure, use the indicative. Avoid it after acredito que in positive sentences. Avoid it after penso que or acho que. These phrases usually take the indicative mood. They express a firm opinion or belief. Do not use it for things happening right now. If you see it, it is a fact. Facts live in the indicative world. The subjunctive is too shy for facts. It prefers the shadows of doubt. Think of the indicative as a photograph. Think of the subjunctive as a painting.

Many people forget the que. This word is the glue of the sentence. Do not forget to change the vowel. Using -a for an -ar verb is common. This makes it sound like the indicative. People often forget the irregular verbs. Ser becomes seja, not sê. Ir becomes vá, not ia. Another mistake is using it after acho que. This is a classic learner error. Native speakers will still understand you. But you want to sound like a local. Practice the irregulars until they feel natural. They are the most common verbs anyway. Do not let the "opposite vowel" rule confuse you.

Compare Acho que ele vem with Não acho que ele venha. The first one is a belief. The second one is a doubt. The first uses the indicative mood. The second uses the subjunctive mood. See how the negative changes everything? Compare Espero o autocarro with Espero que o autocarro venha. The first is a physical action. The second is a mental wish. The first is simple and direct. The second is complex and emotional. One is about reality. The other is about hope. This is the core of Portuguese logic.