The most common question a learner has about the personal infinitive is not how to form it — the formation rule is mercifully simple — but when to use it. When should you inflect the infinitive, and when should you leave it bare? This page is the answer, and it is the page you will return to most often in this set.
The rules can be reduced to a single idea: the personal infinitive exists to mark a subject. When the subject is already clear from the main clause, the bare infinitive is enough. When the subject is new, specific, or ambiguous, inflection does the work that a full que + subjunctive clause would otherwise have to do.
The core rule in one sentence
Use the bare infinitive when the subject is the same as the main clause; use the personal infinitive when the subject is different or needs to be specified.
That is the whole rule. Everything else on this page is refinement, edge cases, and the handful of contexts where both options are grammatical and you have to pick based on register and emphasis.
Quero sair cedo amanhã.
I want to leave early tomorrow. (same subject — I want, I leave)
Quero que saias cedo amanhã.
I want you to leave early tomorrow. (different subject — I want, you leave)
É importante sair cedo.
It's important to leave early. (no specific subject — universal advice)
É importante saíres cedo.
It's important for you to leave early. (specific subject — you)
The first two sentences are the classic same-subject vs different-subject contrast, covered in detail on the subjunctive vs infinitive page. The last two show what the personal infinitive adds on top: even when the main clause has no subject at all (é importante), you can pin down the subject of the subordinate clause with an inflected infinitive.
Rule 1: Same subject — no inflection
When the infinitive's subject is the same as the subject of the main verb, use the bare infinitive. No inflection. Ever.
Quero aprender alemão.
I want to learn German. (I want, I learn)
Tens de estudar mais se queres passar.
You have to study more if you want to pass. (you have to, you study)
Decidimos não ir à festa.
We decided not to go to the party. (we decided, we go)
Writing quero aprendermos alemão or decidimos não irmos is not just unidiomatic — it is ungrammatical. Same-subject infinitives must remain bare.
This holds for all main verbs that take an infinitive complement: querer, preferir, decidir, poder, dever, ter de, precisar de, tentar, conseguir, gostar de, começar a, continuar a, acabar de, and so on. The subject carries over by default.
Rule 2: Different subject — personal infinitive
When the infinitive's subject is different from the main clause, you need to mark that change somehow. Portuguese has two strategies:
- que + subjunctive — the traditional Romance strategy.
- Personal infinitive — the distinctively Portuguese strategy, available after prepositions and impersonal expressions.
Which one you can use depends on the main predicate. Here is the breakdown.
After volition verbs → que + subjunctive (not a bare personal infinitive)
Verbs of direct volition — querer, desejar, preferir — block a bare personal infinitive when the subject changes. They force que + subjunctive.
Quero que venhas cedo.
I want you to come early.
Prefiro que fiques aqui.
I'd rather you stay here.
Desejo que tenhas um bom fim de semana.
I hope you have a nice weekend.
You cannot say quero tu vires cedo or prefiro tu ficares aqui in standard Portuguese. Querer, desejar, preferir take que + subjunctive and nothing else when the subject changes.
Pedir is different. Although pedir is semantically a volition verb, it readily accepts a para + personal infinitive complement alongside the que + subjunctive option. Both are everyday European Portuguese.
Pedi-lhe para chegar a horas.
I asked him to arrive on time. (para + infinitive — same subject reference across the clause)
Pedi aos miúdos para chegarem cedo.
I asked the kids to arrive early. (para + personal infinitive)
Pedi que chegassem cedo.
I asked them to arrive early. (que + imperfect subjunctive — equally correct)
Emotion verbs like lamentar, ter pena, ter medo accept both structures. They are more flexible than volition verbs: que + subjunctive and a direct (or de +) personal infinitive both sound native.
Lamento teres perdido a oportunidade.
I'm sorry you missed the opportunity. (personal infinitive — natural and common)
Lamento que tenhas perdido a oportunidade.
I'm sorry you missed the opportunity. (que + perfect subjunctive — equally natural)
Tenho pena de não poderes vir.
I'm sorry you can't come. (de + personal infinitive)
Tenho medo de eles chegarem tarde.
I'm afraid they'll arrive late. (de + personal infinitive)
The strict blockers are querer, desejar, preferir. Everything else in the volition/emotion family is more welcoming, and the personal infinitive is often the lighter, more colloquial choice.
After impersonal expressions → either option works
After é importante, é preciso, é bom, é difícil, convém, and similar impersonals, both the personal infinitive and que + subjunctive are grammatical. This is a register and emphasis choice.
É importante tu estudares.
It's important for you to study. (personal infinitive — lighter)
É importante que tu estudes.
It's important that you study. (que + subjunctive — slightly more formal)
É melhor nós irmos embora.
We'd better go. (personal infinitive)
É melhor que nós vamos embora.
It's better that we go. (que + subjunctive)
In European Portuguese speech, the personal infinitive is usually the more natural choice. In formal writing, que + subjunctive is slightly more common. Native speakers switch between them without thinking; both versions sound native.
After prepositions → personal infinitive or bare infinitive, depending on the subject
Prepositions like para, sem, antes de, depois de, até, ao take an infinitive complement. Whether that infinitive inflects depends on whether the subject changes.
Para aprender português, preciso de ler muito.
To learn Portuguese, I need to read a lot. (same subject — I want, I learn)
Para tu aprenderes português, precisas de ler muito.
For you to learn Portuguese, you need to read a lot. (subordinate subject tu made explicit)
Saí sem fazer barulho.
I left without making any noise. (same subject)
This is the most common context for the personal infinitive, and it gets its own page: personal infinitive after prepositions.
Rule 3: No subject at all — bare infinitive (generic)
When an impersonal expression is making a generic claim — something true for anyone, not a specific subject — the bare infinitive is preferred:
É importante beber muita água.
It's important to drink a lot of water. (general, for anyone)
É preciso ter paciência com crianças pequenas.
You need to have patience with young children. (general advice)
Não é fácil falar uma língua estrangeira.
It isn't easy to speak a foreign language. (generic)
Switching to a personal infinitive here (é importante bebermos muita água) would narrow the claim from "anyone should drink water" to "we specifically should drink water." Both are grammatical; they just mean different things.
The decision flowchart
Here is the complete decision tree for choosing between bare infinitive, personal infinitive, and que + subjunctive.
Is the subject the same as the main clause?
- Yes → bare infinitive (quero sair, para chegar a horas)
- No → continue to step 2.
Is the main predicate a strict volition verb? (querer, desejar, preferir)
- Yes → que + subjunctive only (quero que venhas). A bare personal infinitive is blocked.
- No → continue to step 3. (Emotion verbs like lamentar, ter pena, ter medo and request verbs like pedir do accept a (preposition +) personal infinitive — see the section above.)
Is there a preposition introducing the infinitive? (para, sem, antes de, depois de, até, ao)
- Yes → personal infinitive (para tu chegares, sem eles saberem)
- No → continue to step 4.
Is there an impersonal evaluation? (é importante, é preciso, é bom, convém)
- Yes → choose between personal infinitive (lighter) and que + subjunctive (slightly more formal). Both are correct.
- No → you probably need que + subjunctive (subjunctive-triggering conjunction like embora, para que, a fim de que, antes que, caso).
When both options are grammatical: register and emphasis
The interesting decisions happen in contexts where both the personal infinitive and que + subjunctive are available — usually after impersonal expressions. Here is how native speakers choose.
Personal infinitive: lighter, more colloquial
É pena não poderes vir.
What a shame you can't come.
Convém chegares cedo.
It's best if you arrive early.
É fundamental eles perceberem o problema.
It's essential that they understand the problem.
These are perfectly natural in speech. They are lighter because the infinitive is shorter than the subjunctive — no que, no inflected finite verb — and the subject pronoun can be omitted or placed right before the infinitive.
Que + subjunctive: slightly more formal or emphatic
É pena que não possas vir.
It's a shame that you can't come.
Convém que chegues cedo.
It is advisable that you arrive early.
É fundamental que eles percebam o problema.
It is essential that they understand the problem.
These sound slightly more weighty. The que introduces a proper finite clause and the subjunctive marks the mood. In formal writing, legal language, and careful speech, que + subjunctive is more common. In everyday conversation, the personal infinitive wins.
Comparison with English
English does something similar in its for + pronoun + to-infinitive construction, but with important differences.
É difícil chegarmos a horas.
It's difficult for us to arrive on time.
É importante tu estudares.
It's important for you to study.
English for us to arrive, for you to study maps reasonably well onto the Portuguese personal infinitive. The difference is that English has to introduce the subject with a preposition (for), whereas Portuguese embeds the subject directly into the verb form. That is what makes Portuguese sentences so compact:
- English: "It's important for them to know the truth." (8 words)
- Portuguese: "É importante saberem a verdade." (4 words)
The personal infinitive is doing the work of English for + them in a single ending. This is why Portuguese native speakers find translations from English often feel clunky — the source language wants to spell things out with prepositions and pronouns, but Portuguese collapses that into a verb ending.
Comparison with Spanish
Spanish has no equivalent of the personal infinitive. Where Portuguese has a choice, Spanish is forced into que + subjunctive every time:
| Spanish (forced) | Portuguese (choice) |
|---|---|
| Es importante que vengas temprano. | É importante vires cedo. / É importante que venhas cedo. |
| Para que yo entienda, explícamelo otra vez. | Para eu perceber, explica-me outra vez. |
| Antes de que salgan, quiero hablar con ellos. | Antes de saírem, quero falar com eles. |
| Sin que se den cuenta. | Sem darem por isso. |
A Spanish speaker learning Portuguese is at risk of reaching for que + subjuntivo in every one of these contexts — producing Portuguese that is grammatical but stylistically heavy. Native Portuguese speakers overwhelmingly prefer the personal infinitive in these prepositional contexts, and the "proper" way to sound like one is to use it.
The one ambiguity: when subject identity is unclear
Sometimes a sentence is genuinely ambiguous without a personal infinitive, and the inflection is what clarifies things. Consider:
O professor pediu para sair.
The teacher asked to leave. (ambiguous — teacher leaves? or someone else?)
O professor pediu para saíres.
The teacher asked for you to leave.
O professor pediu para saírem.
The teacher asked for them to leave.
The first sentence has the teacher as both asker and leaver — same subject, bare infinitive. The second and third specify a different leaver (tu, eles) via the personal infinitive ending.
Here is another case:
Foi bom jantar juntos.
It was nice to have dinner together. (generic, or speaker-inclusive)
Foi bom jantarmos juntos.
It was nice for us to have dinner together. (specifically us — nós)
In the first sentence, "together" already implies more than one person, but the infinitive is bare, so the claim is generic ("it was nice eating together, as a concept"). The second sentence narrows it to nós specifically. A speaker talking to a friend after a pleasant evening would almost certainly use the second form.
Clarifying difficult cases
After verbs of perception — bare infinitive, no inflection
Verbs of perception (ver, ouvir, sentir) can take an infinitive complement with an accusative subject. The subject is marked as an object pronoun, and the infinitive stays bare:
Vi-a sair do escritório.
I saw her leave the office.
Ouvi-os falar sobre o projeto.
I heard them talking about the project.
This is a different construction from the prepositional personal-infinitive pattern. The subject of the infinitive is inside the main clause as a pronoun; the infinitive itself does not inflect.
After deixar, mandar, fazer (causative) — same deal
Deixei-os jogar no jardim.
I let them play in the garden.
Mandei-a voltar para casa.
I had her go back home.
These are also accusative-subject constructions. The infinitive stays bare.
Contrast: prepositional construction with the same verbs
Deixei o recado para eles saberem.
I left the note so they'd know. (personal infinitive — para introduces a new clause)
Here para introduces a subordinate purpose clause with a new subject (eles), so the personal infinitive is required. The syntactic frame is what matters: causative deixar with a direct object takes a bare infinitive; para + subject + inflected infinitive is a different structure entirely.
Common Mistakes
❌ Quero ires ao supermercado.
Incorrect — the strict volition verbs querer, desejar, preferir with a subject change take que + subjunctive, not a bare personal infinitive.
✅ Quero que vás ao supermercado.
I want you to go to the supermarket.
A bare personal infinitive does not appear in the immediate scope of querer, desejar, or preferir. Quero que + subjunctive is the only option. Note that pedir is more flexible and does accept pedir para + personal infinitive (pedi-lhe para chegar cedo).
❌ Para chegarmos cedo, eu tenho de acordar às seis.
Inconsistent — the subordinate and main clause have different subjects.
✅ Para chegarmos cedo, temos de acordar às seis.
For us to arrive early, we have to get up at six.
✅ Para chegar cedo, tenho de acordar às seis.
To arrive early, I have to get up at six.
Make sure the subject of the personal infinitive matches the subject of the main clause when you intend same-subject reference. Chegarmos commits you to nós; if the main clause subject is eu, the infinitive should be bare (chegar).
❌ É importante bebermos muita água.
Grammatical but narrows the claim to nós. If you want a general statement, use the bare form.
✅ É importante beber muita água.
It's important to drink a lot of water. (general advice)
✅ É importante bebermos muita água.
It's important that we drink a lot of water. (specifically us)
Both are grammatical, but they mean different things. Use the bare infinitive for universal claims, the personal infinitive when the subject is specifically nós.
❌ Antes de eles chegar, arruma a casa.
Incorrect — once the subject eles is explicit, the infinitive must be inflected.
✅ Antes de eles chegarem, arruma a casa.
Before they arrive, tidy up the house.
Whenever you have written the subject pronoun, inflect the infinitive.
❌ Vi os miúdos saírem para a rua.
Unusual — verbs of perception take a bare infinitive with an object subject, not a personal infinitive.
✅ Vi os miúdos sair para a rua.
I saw the kids go out into the street.
Perception and causative verbs (ver, ouvir, sentir, deixar, mandar, fazer) take an accusative subject and a bare infinitive. The personal infinitive does not belong in this construction.
Key takeaways
- Same subject → bare infinitive. Different subject → personal infinitive (or que + subjunctive, depending on the context).
- Strict volition verbs (querer, desejar, preferir) block a bare personal infinitive with a subject change. They take que + subjunctive. Request verbs (pedir) and emotion verbs (lamentar, ter pena, ter medo) accept both (para / de +) personal infinitive and que + subjunctive.
- Prepositions (para, sem, antes de, depois de) welcome the personal infinitive whenever the subject differs.
- Impersonal expressions (é importante, é preciso) accept both the personal infinitive and que + subjunctive. The infinitive is lighter; que + subjunctive is slightly more formal.
- Generic claims ("it's important to X" for anyone) use the bare infinitive. Specific claims ("it's important for us to X") use the personal infinitive.
- Perception and causative verbs (ver, ouvir, deixar, mandar) take a bare infinitive with an accusative subject — they never use the personal infinitive.
Next: personal infinitive after prepositions for the most common context, or personal infinitive as subject for the impersonal-expression use.
Related Topics
- Personal Infinitive: OverviewB1 — The infinitivo pessoal — an infinitive that conjugates for person and number — is Portuguese's signature grammatical feature, and one of the things that makes the language feel unlike the rest of Romance.
- Personal Infinitive: FormationB1 — How to build the infinitivo pessoal: take the infinitive and add the personal endings -es, -mos, -em. No stem changes, no irregularities — the only exception is pôr, which keeps its circumflex.
- Personal Infinitive After PrepositionsB1 — The most common use of the infinitivo pessoal: after para, sem, antes de, depois de, até, and ao. Full examples of each, plus clitic placement with pronominal verbs.
- Personal Infinitive as SubjectB2 — Using the inflected infinitive as the subject of a sentence — é importante estudarmos, é bom vocês virem, lermos ajuda a memorizar — and how this competes with the que + subjunctive construction.
- Subjunctive vs InfinitiveB2 — When Portuguese uses an infinitive — impersonal or personal — where other Romance languages force a subjunctive, and how to pick correctly between que + conjuntivo and the infinitive.