Personal Infinitive Usage Differences | Portuguese (Portugal) Grammar

The personal infinitive (infinitivo pessoal, sometimes called the inflected infinitive) is one of the most distinctive features of Portuguese — a verb form that shares the grammar of an infinitive but carries person endings: falar, falares, falar, falarmos, falardes, falarem. No other major Romance language has a productive version of this. What many learners do not realise is that both varieties of Portuguese have it, but they use it differently. European Portuguese (PT-PT) deploys the personal infinitive as a preferred everyday construction in contexts where Brazilian Portuguese (BR) gravitates toward the subjunctive or an indicative subordinate clause. The forms are the same; the habits around them are not.

This page is not about how to conjugate the personal infinitive — see Personal Infinitive Overview and Formation for that. It is about when PT-PT reaches for it and when BR reaches for an alternative, and the subtle stylistic consequences of each choice. For learners at B2, this is one of the hallmarks of sounding genuinely Portuguese rather than Brazilian-trained-speaking-PT-PT. Under-using the personal infinitive is a foreign-sounding tic; over-using it in BR sounds stilted. Both speakers recognise the forms, but the distributional preferences diverge enough that a paragraph of text can often be identified as PT-PT or BR from the ratio alone.

Quick reminder: the forms

Regular verbs take the endings -, -es, -, -mos, -des, -em on the bare infinitive:

Person	falar	comer	partir
eu	falar	comer	partir
tu	falares	comeres	partires
ele / ela / você	falar	comer	partir
nós	falarmos	comermos	partirmos
vós	falardes	comerdes	partirdes
eles / elas / vocês	falarem	comerem	partirem

The critical point: for irregular verbs, the personal infinitive is built on the infinitive stem, not the present or preterite stem. So ser gives sermos, serem (not formos, forem, which are future subjunctive forms built on the preterite stem). This is true in both varieties.

Where PT-PT reaches for the personal infinitive

1. Subject clauses — "É importante / É bom / É necessário"

PT-PT almost always prefers the personal infinitive in subject clauses introduced by an impersonal expression. BR accepts both but often switches to que + subjunctive, especially when the subject is emphasised.

É importante eles estudarem antes do exame.

It's important that they study before the exam. (PT-PT preferred)

É importante que eles estudem antes do exame.

It's important that they study before the exam. (BR preferred, also acceptable in PT-PT)

Both sentences mean the same thing and both are grammatical in both varieties. But if you show the first to ten Portuguese speakers and the second to ten Brazilians, you'll see the preference asymmetry clearly. In a Portuguese newspaper editorial, É importante eles estudarem is routine; in a Brazilian one, you are more likely to find the que-clause.

Será difícil chegarmos a tempo com este trânsito.

It will be difficult for us to arrive on time with this traffic. (PT-PT)

Não vale a pena insistires — ele já decidiu.

It's not worth your insisting — he's already decided. (PT-PT)

2. Clauses with an overt subject different from the main clause

This is the classical environment for the personal infinitive: the subordinate clause has a different subject than the main clause, and PT-PT expresses that subject right next to the infinitive. The personal ending makes the subject unambiguous.

Antes de os alunos entrarem, o professor preparou a sala.

Before the students came in, the teacher prepared the room. (PT-PT)

Antes que os alunos entrassem, o professor preparou a sala.

Before the students came in, the teacher prepared the room. (BR preferred — imperfect subjunctive after 'antes que')

In PT-PT, antes de + personal infinitive is overwhelmingly the default. In BR, antes que + subjunctive is at least as frequent and often more so, especially in writing. Both are fully grammatical in both varieties, but the distribution flips.

Depois de os convidados saírem, limpámos a casa toda.

After the guests left, we cleaned the whole house. (PT-PT)

Para as crianças não adoecerem, vamos fechar as janelas.

So that the children don't get sick, we'll close the windows. (PT-PT — personal infinitive after 'para')

Para que as crianças não adoeçam, vamos fechar as janelas.

So that the children don't get sick, we'll close the windows. (BR — 'para que' + present subjunctive)

3. After prepositions, in general

PT-PT treats preposition + personal infinitive as the default way to express a subordinate clause with its own subject. BR uses the same construction but less consistently and more often switches to a finite clause.

Sem eles saberem o que se passava, organizámos a festa surpresa.

Without them knowing what was happening, we organised the surprise party. (PT-PT)

Sem que eles soubessem o que se passava, organizámos a festa surpresa.

Without them knowing what was happening, we organised the surprise party. (BR alternative with subjunctive)

Ao chegarmos ao aeroporto, percebemos que o voo tinha sido cancelado.

Upon arriving at the airport, we realised the flight had been cancelled. (PT-PT — 'ao' + personal infinitive is standard in both, but especially active in PT-PT)

Por seres tu a pedir, digo que sim.

Since it's you asking, I'll say yes. (PT-PT — 'por' + personal infinitive for cause)

4. As a replacement for the gerund (PT-PT specifically)

This is where the PT-PT/BR split is sharpest. BR uses the gerund (-ndo) very freely: Eles estão dormindo. Saímos correndo. Chegou gritando. PT-PT uses estar a + infinitive for the progressive (see Progressive Differences), and in several gerund contexts prefers preposition + personal infinitive where BR would use the gerund.

Saímos a correr quando começou a chover.

We left running when it started to rain. (PT-PT — 'a + infinitive' where BR uses 'saímos correndo')

Passámos a tarde a conversar no jardim.

We spent the afternoon chatting in the garden. (PT-PT — 'a + infinitive' where BR uses 'conversando')

Por ser cedo, ninguém estava acordado.

Since it was early, nobody was awake. (PT-PT — 'por' + infinitive for cause, where BR might say 'Sendo cedo' with gerund)

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A useful diagnostic: in PT-PT, the sequence a + bare infinitive or por + bare infinitive does the work that BR often assigns to the gerund. The personal endings appear whenever the subject is overt and distinct from the main clause. Listen for this pattern in Portuguese radio and podcasts — it's everywhere.

5. Formal and written registers

Formal PT-PT loves the personal infinitive. Academic writing, legal prose, journalistic op-eds — all feature the construction as a marker of educated style. BR formal writing uses it too, but more sparingly and more often in clear different-subject contexts, rarely as a gerund substitute.

Cumpre aos cidadãos exercerem o seu direito de voto.

It falls to citizens to exercise their right to vote. (PT-PT formal)

Agradecemos a V. Exas. confirmarem a receção da presente.

We would be grateful if you would confirm receipt of this letter. (PT-PT formal correspondence)

Where BR reaches instead

To understand the PT-PT pattern, you have to see what BR does. BR has three main alternatives to the personal infinitive:

Alternative 1: que + subjunctive

Where PT-PT says É importante eles estudarem, BR tends to say É importante que eles estudem. This is the most common swap. BR uses the subjunctive after é importante, é necessário, é bom, é preciso, é difícil, and similar impersonal triggers much more frequently than PT-PT does.

Alternative 2: Temporal conjunction + subjunctive or indicative

Where PT-PT says antes de os alunos entrarem, BR uses antes que os alunos entrassem (subjunctive) or simply antes dos alunos entrarem (with the same personal infinitive — BR does allow it here, but often drops the contracted dos too).

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BR speakers do use the personal infinitive after antes de, depois de, para, etc. — it is fully grammatical in BR. The difference is frequency and stylistic weight. Educated BR writing uses it; everyday BR speech often avoids it.

Alternative 3: Gerund

Where PT-PT says Saímos a correr, BR says Saímos correndo. Where PT-PT says Passei o dia a trabalhar, BR says Passei o dia trabalhando. The BR gerund covers huge swathes of PT-PT's a + infinitive territory.

Side-by-side paragraph

Same content, rendered naturally in each variety. The lexical level is identical; the subordination strategies differ.

PT-PT: > Antes de saírem de casa, os pais pediram às crianças para fecharem as janelas. Sem o irmão mais velho saber, os gémeos passaram a tarde a jogar no quintal. Ao voltarem, os pais descobriram a confusão. Para não zangarem o pai, os miúdos limparam tudo antes de ele chegar.

BR: > Antes que saíssem de casa, os pais pediram para que as crianças fechassem as janelas. Sem que o irmão mais velho soubesse, os gêmeos passaram a tarde jogando no quintal. Ao voltarem, os pais descobriram a confusão. Para não irritar o pai, a molecada limpou tudo antes de ele chegar.

Notice the BR paragraph still uses Ao voltarem and antes de ele chegar — these personal infinitive structures survive in BR too — but the rest has moved to que + subjunctive or gerund. The PT-PT paragraph uses the personal infinitive four times; the BR paragraph, twice.

Why PT-PT prefers the personal infinitive

This isn't arbitrary. Several factors push PT-PT toward the construction:

A living future subjunctive. PT-PT preserves the future subjunctive in everyday speech (Future Subjunctive Differences), so the subjunctive system as a whole is healthy and speakers don't avoid it. But because the personal infinitive provides a tidy alternative for non-hypothetical subordinates with a clear subject, it often wins in practice.
Weaker use of the bare gerund in non-progressive contexts. BR uses the gerund productively for manner, simultaneity, cause, and progressive aspect. PT-PT reserves the gerund mostly for specific literary or regional uses and routes the rest through a + infinitive, por + infinitive, ao + infinitive. Once those paths open, the personal endings follow naturally.
Pragmatics of subject tracking. PT-PT's clitic system and verb morphology reward explicit subject marking at every level. When a subordinate clause has a new subject, PT-PT speakers tend to mark it — and the personal infinitive lets them do so without a full finite clause.
Register continuity. PT-PT speech and writing sit closer together (Written vs Spoken), so a literary-looking construction like É difícil chegarmos a tempo doesn't feel out of place in conversation. In BR, that sentence sounds a notch more formal than its que-clause equivalent.

When NOT to use the personal infinitive

Even in PT-PT, the personal infinitive is not used when:

The subject is the same as the main clause and there is no risk of ambiguity. Quero estudar ("I want to study"), not Quero eu estudar. The bare infinitive is correct.
The subordinate is a direct object of a perception verb (ver, ouvir, sentir) without a preposition — these usually take a bare infinitive or an adjective-style structure: Vi-os sair is preferred in PT-PT over Vi-os saírem, though both appear.
Fixed expressions have their own lexicalised form: a saber, ao fim e ao cabo. Don't conjugate these.
Modal + infinitive chains stay bare: Podemos ir, not Podemos irmos.

Queremos sair mais cedo hoje.

We want to leave earlier today. (same subject — bare infinitive)

Queremos que eles saiam mais cedo hoje.

We want them to leave earlier today. (different subject — subjunctive, not personal infinitive, because 'querer' takes a finite 'que'-clause)

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Crucial contrast: querer, dizer (= tell), pedir, mandar + subordinate take que + subjunctive, not the personal infinitive — in both varieties. The personal infinitive is for environments introduced by an impersonal trigger (é + adjective), a preposition (de, para, sem, por, ao, até), or as an independent subject clause.

A diagnostic: the PT-PT paragraph test

If you write a paragraph of Portuguese and count how many times you used the personal infinitive vs how many times you used a que-subjunctive or gerund, you should land in a PT-PT-shaped range: something like 3-5 personal infinitives per 100 verb forms in a prose paragraph, ideally 1-2 of them as gerund-replacements via a + infinitive. If you're at 0, you sound Brazilian-trained. If you're at 10+, you sound stilted even for PT-PT. The middle band is the target.

Common mistakes

Mistake 1: Avoiding the personal infinitive in PT-PT because BR avoids it.

❌ É importante que nós estudemos mais.

Grammatical but BR-flavoured. Portuguese speakers rarely write this.

✅ É importante estudarmos mais.

It's important for us to study more. (PT-PT natural)

The que-subjunctive isn't wrong, but learners moving to PT-PT should actively practise the personal-infinitive construction to rewire their defaults.

Mistake 2: Using the personal infinitive with the same subject as the main clause.

❌ Eu quero eu ir ao cinema.

Incorrect — same subject, no personal infinitive needed.

✅ Eu quero ir ao cinema.

I want to go to the cinema. (bare infinitive — same subject)

The personal infinitive requires either a change of subject or an impersonal frame. Same-subject complements take the bare infinitive.

Mistake 3: Using the personal infinitive after querer / pedir / mandar + que.

❌ Quero que vocês virem mais cedo.

Incorrect — 'virem' here is the personal infinitive of 'vir' (and also the future subjunctive 3pl of 'ver', easily confusable). After 'querer que', the dependent clause needs the present subjunctive 'venham'.

✅ Quero que vocês venham mais cedo.

I want you to come earlier. (present subjunctive after 'querer que')

Volitional verbs (querer, pedir, mandar, exigir) take que + subjunctive in both varieties. The personal infinitive does not appear here.

Mistake 4: Building the personal infinitive on the wrong stem for irregular verbs.

❌ Antes de fômos, avisa-me.

Incorrect — 'fômos' doesn't exist; confusion with preterite 'fomos'.

✅ Antes de irmos, avisa-me.

Before we go, let me know. (personal infinitive of 'ir' is 'irmos' — built on the infinitive 'ir')

Always build the personal infinitive on the infinitive stem, never on a conjugated form. Sermos, estarmos, termos, irmos, virmos, pormos — not the future-subjunctive-looking forms.

Mistake 5: Over-applying the personal infinitive in BR.

❌ (BR context) É bom tu estudares todos os dias.

Grammatical but sounds stilted and Portuguese-flavoured in BR conversation.

✅ (BR context) É bom você estudar todos os dias. / É bom que você estude todos os dias.

It's good for you to study every day. (BR natural options)

If you're a PT-PT-trained speaker writing for a BR audience, tone down the personal infinitive. It comes across as imported.

Key takeaways

The personal infinitive exists in both varieties — it is not a PT-PT exclusive. The difference is usage frequency and stylistic default.
PT-PT prefers the personal infinitive in: subject clauses (É importante eles estudarem), after prepositions with a different subject (antes de eles entrarem), and as a gerund-replacement (saímos a correr).
BR prefers alternatives: que
- subjunctive (É importante que eles estudem), temporal conjunction + subjunctive (antes que entrassem), or the gerund (saímos correndo).
The construction is built on the infinitive stem for all verbs, including irregulars — sermos, irmos, termos, never the preterite form.
Same-subject complements take the bare infinitive in both varieties. Volitional verbs (querer, pedir, mandar) take que
- subjunctive, not the personal infinitive.
Under-using the personal infinitive in PT-PT is the single most common structural tell of a BR-trained learner. Actively practise the construction when retuning to PT-PT.