Brazilian Portuguese expresses modality — can, should, want, need, know how to, prefer, try, manage — with a beautifully simple pattern: a modal verb conjugated + an infinitive that stays unchanged. Posso falar (I can speak), quero comer (I want to eat), devo ir (I should go). Only the first verb changes for person and tense; the second verb is always a bare infinitive. This is the everyday engine of Portuguese, and the structure maps almost perfectly onto English "can do," "want to do," "should do."
Almost perfectly — and the place where it breaks is exactly where this page earns its keep. One verb, gostar, demands a little word that English never uses: de. Gosto *de viajar. English speakers omit this *de constantly. Stamp it out early and your Portuguese jumps a level.
The pattern: conjugated modal + bare infinitive
The structure is: [modal verb, conjugated] + [main verb, infinitive]. No preposition is needed for most modals, and the main verb never changes form no matter who the subject is.
Posso falar com você um minuto?
Can I speak with you for a minute?
Devo ir agora, já está tarde.
I should go now, it's already late.
Quero comer alguma coisa antes de sair.
I want to eat something before going out.
Notice that in each, the second verb (falar, ir, comer) is an infinitive, identical to its dictionary form. You do not conjugate it. Whether the subject is eu, você, or eles, the main verb stays put — only the modal carries the person and tense.
The core modals
Here are the most useful modal-type verbs in Brazilian Portuguese. Note carefully which ones take a preposition before the infinitive — most take none, but a few require a or de.
| Modal (eu form) | Meaning | Connector | Example |
|---|---|---|---|
| posso (poder) | can / may | — (none) | Posso entrar? — May I come in? |
| devo (dever) | should / must | — (none) | Devo estudar mais. — I should study more. |
| quero (querer) | want | — (none) | Quero dormir. — I want to sleep. |
| preciso (precisar) | need | — (or de + noun) | Preciso trabalhar. — I need to work. |
| sei (saber) | know how to | — (none) | Sei nadar. — I know how to swim. |
| prefiro (preferir) | prefer | — (none) | Prefiro ficar em casa. — I prefer to stay home. |
| tento (tentar) | try | — (none) | Tento entender. — I try to understand. |
| consigo (conseguir) | manage / be able to | — (none) | Consegui terminar. — I managed to finish. |
| gosto de (gostar) | like to | de (obligatory!) | Gosto de viajar. — I like to travel. |
Eu sei nadar, mas não sei mergulhar.
I know how to swim, but I don't know how to dive.
Finalmente consegui terminar o relatório.
I finally managed to finish the report.
Prefiro andar a pegar o ônibus lotado.
I'd rather walk than take the crowded bus.
A note on saber vs. poder: both can translate as English "can," but they are not interchangeable. Saber + infinitivo means to know how to (a learned skill): sei dirigir = "I can/know how to drive." Poder + infinitivo means to be allowed to / have the possibility: posso dirigir = "I'm allowed to drive / I can drive (it's possible now)." English collapses both into "can"; Portuguese keeps them apart. See poder and querer / saber for the full conjugations.
Eu sei cozinhar, mas hoje não posso, estou sem tempo.
I know how to cook, but today I can't — I'm out of time.
The big one: gostar DE
This is the most systematic error English speakers make, so it gets its own section. Gostar never connects directly to its complement. It always requires the preposition de — before a noun and before an infinitive.
Eu gosto de viajar nas férias.
I like to travel on vacation.
Você gosta de acordar cedo?
Do you like waking up early?
Eles gostam de jogar futebol no domingo.
They like to play soccer on Sundays.
Why does gostar behave this way when querer, preferir, and the others don't? Because gostar is not really a modal at all — it's an ordinary verb that governs the preposition de, the same way English "to approve of" or "to dream of" governs "of." In Portuguese, gostar simply always takes de before its object: gosto de chocolate (I like chocolate), gosto de você (I like you), gosto de viajar (I like to travel). The infinitive is just another kind of object, so it also gets the de.
The mirror image is precisar. With an infinitive, precisar usually takes no preposition (preciso trabalhar), but with a noun it takes de (preciso de ajuda, "I need help"). Don't overgeneralize the de to every modal — it's obligatory for gostar, optional/contextual for precisar, and absent for the rest.
Preciso de ajuda para carregar isso.
I need help carrying this. (precisar DE + noun)
Preciso trabalhar amanhã cedo.
I need to work early tomorrow. (precisar + infinitive, no preposition)
Tense lives on the modal
Because only the first verb conjugates, you express all the tense and mood on the modal. The infinitive is frozen. This makes the past, future, and conditional easy.
| Tense | Example | Gloss |
|---|---|---|
| Presente | Eu quero sair. | I want to go out. |
| Pretérito perfeito | Eu quis sair. | I wanted to go out. |
| Pretérito imperfeito | Eu queria sair. (also a polite "I'd like") | I wanted / would like to go out. |
| Futuro do pretérito | Eu poderia sair, mas não quero. | I could go out, but I don't want to. |
Queria falar com o gerente, por favor.
I'd like to speak with the manager, please. (polite imperfeito)
That queria (imperfect of querer) used for a polite request is worth knowing: queria um café ("I'd like a coffee") is softer and more courteous than the blunt quero um café. Likewise poderia (conditional of poder) softens a request: poderia me ajudar? ("could you help me?"). For obligation specifically — ter que and dever — see Ter que / Dever.
Common Mistakes
These are the real transfer errors English speakers make: dropping gostar's de, conjugating the second verb, and confusing saber with poder.
❌ Eu gosto viajar.
Incorrect — gostar requires 'de' before its complement.
✅ Eu gosto de viajar.
I like to travel.
❌ Eu gosto muito Lisboa.
Incorrect — missing 'de' after gostar (also true with nouns).
✅ Eu gosto muito de Lisboa.
I really like Lisbon.
❌ Eu quero como pizza.
Incorrect — the second verb must be an infinitive (comer), not a conjugated form.
✅ Eu quero comer pizza.
I want to eat pizza.
❌ Posso nadar muito bem, aprendi quando era criança.
Wrong modal for a skill — for 'know how to', use saber, not poder.
✅ Sei nadar muito bem, aprendi quando era criança.
I can swim very well; I learned as a kid.
❌ Nós devemos a estudar mais.
Incorrect — 'dever' takes no preposition; the 'a' is intruding (likely transfer from começar a).
✅ Nós devemos estudar mais.
We should study more.
A final caution: do not assume every "want/need/like" verb takes the same connector. The safe habit is to memorize each verb with its connector as a unit — gostar de, precisar de (+ noun), começar a, dever (nothing), poder (nothing). The preposition is part of the verb's identity, not an afterthought.
Key Takeaways
- Modality = conjugated modal + bare infinitive. Only the first verb changes for person and tense.
- Most modals (poder, dever, querer, saber, preferir, tentar, conseguir) take no preposition.
- Gostar always requires de before its complement — noun or infinitive: gosto de viajar. This is the #1 English-speaker error.
- Saber + infinitivo = know how to (a skill); poder + infinitivo = be allowed / be possible. English "can" covers both.
- Tense and politeness ride on the modal: queria and poderia are softened, courteous requests.
Now practice Portuguese
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Start learning Portuguese→Related Topics
- Periphrastic Verb Constructions: OverviewA1 — A tour of the verb + verb constructions that dominate spoken Brazilian Portuguese, with the key BR vs. European Portuguese contrasts.
- Ter que + Infinitivo / Dever + Infinitivo (Obligation)A2 — How Brazilian Portuguese expresses obligation and necessity — ter que, ter de, dever, and precisar plus an infinitive.
- Present Indicative of PoderA1 — How to conjugate poder (can, may, be able to) in the Brazilian Portuguese present, the three meanings it covers, and the everyday 'pode ser'.
- Present Indicative of Querer and SaberA2 — How to conjugate querer (want) and saber (know) in the Brazilian Portuguese present, the bare quer form, and saber vs conhecer.
- Começar a / Parar de / Continuar + InfinitivoA2 — Phase-marking verbs in Brazilian Portuguese — começar a, parar de, continuar, voltar a, deixar de — and the prepositions each one takes.