Expressing Opinions | Portuguese (Portugal) Grammar

Expressing an opinion in Portuguese is not just a matter of choosing a phrase — it is a three-dimensional decision about register, certainty, and mood. Do you want to sound tentative or assertive? Casual or formal? And crucially: is your belief affirmative or negated? Because European Portuguese has a strict rule that flips the subordinate clause from the indicative to the subjunctive the moment you put não in front of your belief verb. Acho que ele vem (indicative) means "I think he's coming". Não acho que ele venha (subjunctive) means "I don't think he's coming". This small structural difference is one of the most important in the language.

This page walks through the full opinion repertoire, graded from tentative to assertive and from casual to formal, and then explains the mood rule that governs them all.

The default: tentative opinion verbs

The most common opinion verbs in European Portuguese are the tentative ones — achar, crer, pensar, parecer, supor, imaginar. All of them project a belief rather than asserting a fact, and all of them (when affirmative) take the indicative in the subordinate clause.

Acho que ele tem razão.

I think he's right.

Creio que a reunião é amanhã.

I believe the meeting is tomorrow.

Penso que já falámos sobre isto.

I think we've already talked about this.

Parece-me que está a exagerar.

It seems to me that you're exaggerating.

Diria que temos de esperar mais um pouco.

I would say we have to wait a bit more.

Suponho que não quer saber a verdade.

I suppose he doesn't want to know the truth.

Imagino que esteja muito cansado depois da viagem.

I imagine he's very tired after the trip.

Admito que não li o livro todo.

I admit I haven't read the whole book.

Tenho a impressão de que nos cruzámos antes.

I have the impression we've crossed paths before.

Note parecer's peculiar structure: parece-me que X — literally "it seems to me that X". Parecer takes an indirect object pronoun (me, te, lhe, nos, vos, lhes), and the word order in PT-PT is parece-me with the pronoun hyphenated after the verb. In Brazilian Portuguese you would hear me parece, with the pronoun before.

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By far the most frequent opinion verb in European Portuguese is achar. Acho que sim (I think so), acho que não (I don't think so), acho que tens razão (I think you're right). Use it as your default.

Asserting confidence

When you want to stake a stronger claim, Portuguese has a separate register of phrases. These are not tentative — they project certainty, and they are followed by the indicative.

Tenho a certeza de que não foi ele.

I'm sure it wasn't him.

Sem dúvida que é a melhor solução.

Without a doubt it's the best solution.

Estou convencido de que vai correr bem.

I'm convinced it's going to go well.

De certeza que isto funciona.

For sure this works.

Claramente, foi um engano.

Clearly, it was a mistake.

Aliás, é exatamente o que eu ia dizer.

In fact, that's exactly what I was going to say.

Watch for the construction ter a certeza de que — literally "to have the certainty of that". The de is obligatory in European Portuguese; dropping it (tenho a certeza que) is heard but considered informal/careless in writing. Aliás is a wonderful discourse particle that signals "in fact" or "indeed", often used to add emphasis to a preceding claim.

Formal opinion framings

In writing, in academic contexts, or in more formal speech, Portuguese has a set of elevated opinion markers. These are the phrases you will find in newspaper editorials, political speeches, and university essays.

Na minha opinião, a reforma é necessária.

In my opinion, the reform is necessary.

A meu ver, estamos a ir na direção certa.

In my view, we're heading in the right direction.

Na minha perspetiva, falta um passo fundamental.

From my perspective, there's a fundamental step missing.

Em meu entender, a questão é mais complexa.

As I understand it, the issue is more complex.

Do meu ponto de vista, a proposta é arriscada.

From my point of view, the proposal is risky.

Defendo que devemos investir na educação.

I argue that we should invest in education.

Sou de opinião que este método é mais eficaz.

I hold the view that this method is more effective.

A meu juízo, a decisão foi acertada.

In my judgment, the decision was right.

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Notice a meu ver, em meu entender, a meu juízo — these are fixed formulas where the possessive meu/minha goes after the noun with no article. You cannot say ao meu ver or no meu entender; these are set phrases with frozen word order.

Hedging: softening the stake

The middle ground between tentative belief and formal stake is hedged opinion — where you make clear that what follows is just your view, without pretending to certainty. This is the territory of para mim, pessoalmente, eu cá.

Se me perguntas, diria que ele não vem.

If you ask me, I'd say he's not coming.

Eu cá acho que isto não vai dar em nada.

Personally I think this isn't going to lead anywhere.

Para mim, o melhor era ficarmos em casa.

For me, the best thing would be to stay home.

Pessoalmente, prefiro o original.

Personally, I prefer the original.

Se bem me lembro, foi ela que o disse.

If I remember correctly, she was the one who said it.

Como eu vejo, estamos a dar voltas ao mesmo assunto.

The way I see it, we're going in circles on the same topic.

The eu cá construction is a specifically European Portuguese intensifier. Cá (here) in this position emphasizes the speaker — "I for my part", "as for me". Eu cá acho, eu cá penso, eu cá não faria isso. It is conversational and a little emphatic, but perfectly standard.

Asking for someone else's opinion

O que achas disso?

What do you think of that?

Qual é a tua opinião?

What's your opinion?

O que pensas disto?

What do you think about this?

Tu que dizes?

What do you say?

Tu, o que achas?

You — what do you think?

Como é que vês as coisas?

How do you see things?

Concordas ou não?

Do you agree or not?

The most natural conversational opener is o que achas? — simple, casual, universally used. In more formal settings, qual é a sua opinião sobre X? is the polite alternative. The informal-plus-emphatic tu, o que achas? (comma after the pronoun, strong emphasis on tu) is used when you want to press someone specifically for their view.

European Portuguese has a specific construction for presumption — stating what you think must be the case. This uses the modal dever (must), sometimes with de in the traditional form dever de.

Devem ter razão, já pensaram bem nisto.

They must be right, they've already thought this through.

Há de ser assim, não vejo outra explicação.

It must be that way, I don't see another explanation.

Deve estar certo, tu verificaste.

It must be right, you checked.

Hão de chegar a tempo, não te preocupes.

They'll definitely get there on time, don't worry.

The construction haver de + infinitive (há de ser, hão de chegar) expresses a strong presumption or near-certain prediction. It is distinctively European Portuguese — in Brazil you are more likely to hear deve chegar or the simple future chegarão.

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The traditional form dever de + infinitive for presumption (deve de estar certo) is still heard, especially in older speech and in writing. Modern usage usually drops the de (deve estar certo), but both are correct.

The mood rule: affirmative vs negated belief

This is the single most important grammatical point on this page. European Portuguese follows a strict rule about which mood appears in the subordinate clause after an opinion verb, and the rule is governed by whether the belief is affirmed or negated.

Affirmative belief → indicative

When you affirm a belief — acho que, penso que, creio que, parece-me que — the subordinate clause is in the indicative. The logic is that you are committing to the content as (from your perspective) a fact.

Acho que ele vem amanhã.

I think he's coming tomorrow.

Penso que a ideia é boa.

I think the idea is good.

Creio que já terminámos.

I believe we've already finished.

Parece-me que está a chover.

It seems to me it's raining.

Notice that all these subordinate verbs — vem, é, terminámos, está — are indicative. Even though the main verb is one of belief, the speaker is committing to the content as their belief about reality.

Negated belief → subjunctive

The moment you put não in front of the opinion verb, the subordinate clause flips to the subjunctive. The logic is that you are now denying your commitment — the content is in the realm of uncertainty.

Não acho que ele venha amanhã.

I don't think he's coming tomorrow.

Não penso que a ideia seja boa.

I don't think the idea is good.

Não creio que já tenhamos terminado.

I don't believe we've already finished.

Não me parece que esteja a chover.

It doesn't seem to me that it's raining.

Look at the switched verbs: vem → venha, é → seja, terminámos → tenhamos terminado, está → esteja. All subjunctive. This is not a stylistic choice; it is an obligatory grammatical rule in standard European Portuguese.

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The mood flip after não acho que / não penso que / não creio que is one of the clearest subjunctive triggers in Portuguese. It is obligatory in writing and standard in educated speech. If you want to sound native, internalize this.

Questions: either mood is possible

When the belief verb is in a question, either the indicative or the subjunctive is acceptable, depending on how skeptical you are about the content. An indicative question is a neutral inquiry; a subjunctive question signals doubt.

Achas que ele vem? (neutral)

Do you think he's coming?

Achas que ele venha? (skeptical)

Do you (really) think he's coming?

The difference is subtle but real. The second version implies the speaker has doubts and wants the interlocutor to reflect on them.

What counts as "negated belief"?

The mood-flip rule applies not just to não acho que but to any construction that denies or questions the certainty of the belief. Doubt verbs (duvidar que) always take the subjunctive, even affirmative:

Duvido que ele venha.

I doubt he's coming.

Não creio que seja possível.

I don't think it's possible.

Não é certo que tenha razão.

It's not certain that he's right.

Common mistakes

❌ Eu opinião que é melhor esperar.

Incorrect — *opinião* is a noun, not a verb. You cannot say *eu opinião*.

✅ Na minha opinião, é melhor esperar. / Acho que é melhor esperar.

In my opinion, it's better to wait. / I think it's better to wait.

❌ Não acho que ele tem razão.

Incorrect — after negated belief, the subordinate clause takes the subjunctive, not the indicative.

✅ Não acho que ele tenha razão.

I don't think he's right.

❌ Eu penso que sim.

Stiff — not wrong, but *acho que sim* is far more natural in casual European Portuguese. *Eu penso que* sometimes reads as translated-from-English.

✅ Acho que sim.

I think so.

❌ Tenho a certeza que vai correr bem.

Careless in formal contexts — European Portuguese requires *de que* after *ter a certeza*.

✅ Tenho a certeza de que vai correr bem.

I'm sure it's going to go well.

❌ Na minha opinion...

Incorrect — *opinion* is an English word. The Portuguese is *opinião*.

✅ Na minha opinião...

In my opinion...

Register and tone summary

Register	Phrases	When to use
Informal tentative	acho que, parece-me que, eu cá acho	everyday conversation
Neutral assertive	tenho a certeza de que, sem dúvida que	conversation when you're confident
Formal stake	na minha opinião, a meu ver, defendo que	writing, presentations, debates
Academic	em meu entender, do meu ponto de vista, a meu juízo	academic or official writing
Hedged	para mim, pessoalmente, se me perguntas	softening a potentially controversial view

Key takeaways

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The core opinion verb in European Portuguese is achar, not pensar. Acho que sim, acho que não, acho que tens razão. Using penso que everywhere is a common learner mistake and sounds translated from English.

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Affirmative belief takes the indicative; negated belief takes the subjunctive. Acho que vem → não acho que venha. This mood flip is not optional in educated European Portuguese. Learn the pair: indicative for affirmation, subjunctive for denial.

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Match register to context. Eu cá acho que... at a dinner table; Na minha perspetiva... in an essay. Mixing registers makes your Portuguese sound either stiff (formal phrases in casual speech) or flippant (casual phrases in formal writing).