Pensar means to think — but specifically in the sense of reasoning, reflecting, or having something on your mind. It is a completely regular -ar verb, so once you know the endings of falar you already know how to conjugate pensar. The hard part is not the conjugation; it is knowing when to use pensar instead of achar, and which preposition follows it. This page handles both.
Why pensar is easy to conjugate but tricky to use
Conjugation-wise, pensar hides no surprises. The stem pens- never changes its spelling or its sound, the theme vowel is a, and the endings are the standard first-conjugation set. English speakers stumble not on the forms but on the meaning split: English uses one verb, to think, for two completely different mental acts — reasoning ("Let me think") and holding an opinion ("I think it's a good idea"). Portuguese splits these between pensar (to reflect, to ponder, to have on one's mind) and achar (to reckon, to be of the opinion). Getting this wrong is the single most common error English speakers make with pensar.
Presente do indicativo
| Pronoun | Form |
|---|---|
| eu | penso |
| tu | pensas |
| você / ele / ela | pensa |
| nós | pensamos |
| vocês / eles / elas | pensam |
Eu penso em você o dia inteiro.
I think about you all day long.
Deixa eu pensar um pouco antes de responder.
Let me think a bit before I answer.
Pretérito perfeito
| Pronoun | Form |
|---|---|
| eu | pensei |
| tu | pensaste |
| você / ele / ela | pensou |
| nós | pensamos |
| vocês / eles / elas | pensaram |
As with all -ar verbs, pensamos (nós) is identical in the present and the preterite — only context tells you which tense is meant.
Nunca pensei que fosse tão difícil largar o cigarro.
I never thought quitting smoking would be so hard.
A gente pensou em ir pra praia, mas começou a chover.
We thought about going to the beach, but it started raining.
Pretérito imperfeito
| Pronoun | Form |
|---|---|
| eu | pensava |
| tu | pensavas |
| você / ele / ela | pensava |
| nós | pensávamos |
| vocês / eles / elas | pensavam |
Note the accent on pensávamos (nós) — every -ar verb carries the stress mark here, and English speakers routinely drop it.
Quando eu era criança, pensava que a Lua me seguia.
When I was a kid, I thought the Moon was following me.
Futuro do presente & futuro do pretérito (conditional)
Both are built on the full infinitive pensar-.
| Pronoun | Futuro do presente | Futuro do pretérito |
|---|---|---|
| eu | pensarei | pensaria |
| tu | pensarás | pensarias |
| você / ele / ela | pensará | pensaria |
| nós | pensaremos | pensaríamos |
| vocês / eles / elas | pensarão | pensariam |
In everyday speech the simple future gives way to ir + infinitive: vou pensar rather than pensarei. (informal)
Vou pensar no seu convite e te respondo amanhã.
I'll think about your invitation and get back to you tomorrow.
No seu lugar, eu pensaria duas vezes antes de aceitar.
If I were you, I'd think twice before accepting.
Presente do subjuntivo
-ar verbs flip to -e endings in the present subjunctive.
| Pronoun | Form |
|---|---|
| eu | pense |
| tu | penses |
| você / ele / ela | pense |
| nós | pensemos |
| vocês / eles / elas | pensem |
Espero que você pense bem antes de tomar essa decisão.
I hope you think it over before making this decision.
Imperfeito & futuro do subjuntivo
| Pronoun | Imperfeito do subjuntivo | Futuro do subjuntivo |
|---|---|---|
| eu | pensasse | pensar |
| tu | pensasses | pensares |
| você / ele / ela | pensasse | pensar |
| nós | pensássemos | pensarmos |
| vocês / eles / elas | pensassem | pensarem |
Se você pensasse mais nos outros, seria mais feliz.
If you thought about others more, you'd be happier.
Quando você pensar em desistir, lembra do porquê começou.
Whenever you think about giving up, remember why you started.
Imperativo
| Pronoun | Afirmativo | Negativo |
|---|---|---|
| tu | pensa | não penses |
| você | pense | não pense |
| nós | pensemos | não pensemos |
| vocês | pensem | não pensem |
In Brazil the tu affirmative pensa is heard everywhere, even from speakers who otherwise use você: "Pensa bem!" ("Think hard about it!"). (informal)
Non-finite forms
| Form | Result |
|---|---|
| Infinitivo | pensar |
| Infinitivo pessoal (nós) | pensarmos |
| Infinitivo pessoal (vocês / eles) | pensarem |
| Gerúndio | pensando |
| Particípio | pensado |
Which preposition: em, sobre, or que?
This is where English interference bites. Pensar takes different prepositions depending on the kind of thinking:
- pensar em — to think about something/someone (the thing on your mind). This is by far the most common pattern: penso em você, pensar no futuro, pensar nas contas.
- pensar sobre — to think about / reflect on a topic, often something abstract or debatable. Slightly more deliberate and intellectual than em: pensar sobre a vida, pensar sobre o problema.
- pensar que — to think that (introducing a clause). Penso que vai dar certo. Here pensar drifts close to achar, and many Brazilians would use achar instead in casual speech.
Para de pensar nisso, você não tem culpa de nada.
Stop thinking about that, none of it is your fault.
O professor pediu que a gente pensasse sobre o que é justiça.
The teacher asked us to reflect on what justice is.
Pensar vs achar — the opinion split
The clearest way to feel the difference: achar answers "What's your take?" while pensar describes the mental act of considering. Compare:
Acho que esse filme é chato. (opinion)
I think this movie is boring.
Tô pensando em assistir esse filme hoje. (consideration)
I'm thinking about watching this movie today.
In the first sentence you could not naturally swap in penso — a Brazilian would hear "penso que esse filme é chato" as oddly formal or bookish. In the second you could not use acho, because there is no opinion being offered, only a plan being weighed. See the page on achar for the full contrast.
Common Mistakes
❌ Eu penso esse restaurante é ótimo.
Incorrect — for an opinion use achar, and you need que before a clause.
✅ Eu acho que esse restaurante é ótimo.
I think this restaurant is great.
❌ Penso você toda hora.
Incorrect — pensar needs the preposition em before the thing on your mind.
✅ Penso em você toda hora.
I think about you all the time.
❌ Quando eu era criança, pensava → 'pensaba'.
Incorrect — that's Spanish; Portuguese -ar imperfect is -ava, not -aba.
✅ Quando eu era criança, pensava muito nisso.
When I was a kid, I thought about that a lot.
❌ Espero que você pensa melhor.
Incorrect — after espero que you need the subjunctive pense.
✅ Espero que você pense melhor.
I hope you think it over better.
❌ Nós pensávamos → 'pensavamos' (no accent).
Incorrect — the nós imperfect must carry the accent: pensávamos.
✅ Nós pensávamos diferente naquela época.
We used to think differently back then.
Key Takeaways
- Pensar is a fully regular -ar verb; the stem pens- never changes.
- Use pensar for reflecting/having on your mind, achar for opinions.
- The default preposition is em (pensar em você); sobre for reflecting on a topic.
- Mind the accent in pensávamos and the subjunctive pense.
Now practice Portuguese
Reading grammar gets you part of the way. The exercises are where it sticks — free, no signup needed.
Start learning Portuguese→Related Topics
- AcharA1 — Full conjugation and usage reference for 'achar' (to think, to find) — the most colloquial BR verb for stating an opinion.
- First Conjugation: -ar VerbsA1 — The largest and most regular Brazilian Portuguese verb class — endings across the main tenses, high-frequency verbs, and the gostar de trap.
- Present Indicative: Regular -ar VerbsA1 — How to conjugate regular -ar verbs in the Brazilian Portuguese present indicative — plus the mandatory 'de' after gostar.
- LembrarA1 — Full conjugation and usage reference for 'lembrar' — a regular -ar verb that means both 'to remind' and (reflexively) 'to remember', with a uniquely Brazilian habit of dropping the pronoun.
- Subjunctive after Verbs of Doubt and NegationB1 — Doubt, denial, and negated belief trigger the subjunctive — and the polarity flip that turns acho que into não acho que.