Portuguese is one of a very small number of Romance languages — essentially only Portuguese and Galician, with traces in Sardinian — that possesses a conjugated infinitive. While English, Spanish, French, and Italian have a single, invariant infinitive form (to go, ir, aller, andare), Portuguese has an infinitive that agrees with its subject in person and number. Where Spanish can only say es importante salir (the infinitive salir cannot tell you who is leaving), Portuguese says é importante sairmos ("it's important that we leave") or é importante saírem ("it's important that they leave") — and the verb ending itself tells you who.
This is the infinitivo pessoal, the personal infinitive. It is the single most distinctive grammatical feature of Portuguese, and learning to use it well is what separates a Portuguese speaker who "translates from Spanish" from one who actually thinks in Portuguese. This page is the map of the territory — the paradigm, the four main uses, and the reason the feature exists at all. The pages that follow drill into each of those uses.
An infinitive that conjugates: what it looks like
A regular infinitive is a single, unchanging form. In Portuguese, falar ("to speak") is the dictionary form — and in most Romance languages, that would be the end of the story. But Portuguese allows you to add personal endings to that infinitive, producing a conjugated form that keeps track of its own subject:
| Person | Impersonal infinitive | Personal infinitive |
|---|---|---|
| eu | falar | falar |
| tu | falar | falares |
| ele / ela / você | falar | falar |
| nós | falar | falarmos |
| eles / elas / vocês | falar | falarem |
The 1sg and 3sg forms look identical to the dictionary infinitive. But the tu, nós, and eles forms carry visible personal endings — -es, -mos, -em — that tell you exactly who the subject is.
É importante falarmos com ela antes de ela sair.
It's important that we speak with her before she leaves.
Para tu chegares a horas, tens de sair já.
For you to arrive on time, you need to leave now.
Ao entrarmos na sala, toda a gente se calou.
Upon our entering the room, everyone went quiet.
Notice how in each of these sentences the verb — falarmos, chegares, entrarmos — carries its subject on its sleeve. You do not need a que clause, you do not need a subjunctive, and in each case the construction feels lighter and faster than the alternatives.
Why Portuguese has this — and Spanish doesn't
Medieval Romance languages inherited from Latin a blurry zone between the infinitive (which did not conjugate) and the imperfect subjunctive (which did). Over several centuries of reanalysis in Old Galician-Portuguese, forms from this fuzzy region consolidated into a new paradigm: an infinitive with personal endings. Spanish and French also had glimmers of such a system in medieval texts, but they lost it. Portuguese kept it, standardized it, and expanded its use to become a regular part of the grammar.
The result is that Portuguese has two productive ways of introducing a subordinate clause with a new subject:
- que + subjunctive — the strategy all of Romance shares.
- personal infinitive — the strategy only Portuguese has.
Both are live options in modern Portuguese, and native speakers switch between them constantly. Learning when to reach for each is a major B2 milestone, covered in the dedicated page on subjunctive vs infinitive.
The four main uses
The personal infinitive appears in four main contexts. Each gets its own dedicated page, but here is the landscape:
1. After prepositions
This is the most common context and the one learners encounter first. Prepositions like para, sem, antes de, depois de, até, and ao readily combine with the personal infinitive when the subject of the subordinate clause matters.
Depois de vocês chegarem, abrimos o vinho.
After you arrive, we'll open the wine.
Covered in detail in personal infinitive after prepositions.
2. As the subject of a sentence
Portuguese regularly uses the personal infinitive as the subject of impersonal expressions — é importante, é preciso, é bom, é difícil — when the underlying action has a specific subject.
É importante estudarmos um pouco todos os dias.
It's important that we study a little every day.
É bom vocês virem ver-nos.
It's nice you're coming to see us.
É preciso eles saberem a verdade.
It's necessary that they know the truth.
Covered in detail in personal infinitive as subject.
3. In absolute and adverbial clauses
The personal infinitive can introduce a whole dependent clause on its own, without a preposition, when context makes the relationship clear — often with a temporal, causal, or conditional reading.
A ser verdade o que dizem, temos um problema.
If what they say is true, we have a problem.
This is an advanced use, overlapping with the personal gerund in absolute clauses.
4. Disambiguating subjects in coordinations
When a sentence has multiple clauses with potentially different subjects, the personal infinitive makes the subject crystal clear without forcing you into a heavier construction.
O chefe pediu para chegarmos às nove e saírem às cinco.
The boss asked us to arrive at nine and them to leave at five.
Without personal infinitive marking, the subjects of chegar and sair would be ambiguous. With -mos and -em, the sentence is unambiguous.
Not just a stylistic variant
A common mistake is to assume the personal infinitive is just a "fancy" version of the regular infinitive — something you can sprinkle in for flavor. It is not. In many contexts, the personal infinitive is required because the plain infinitive would be genuinely ambiguous or ungrammatical. In other contexts, both are grammatical but signal different meanings:
É difícil chegar a tempo.
It's difficult to arrive on time. (generic, true for anyone)
É difícil chegarmos a tempo.
It's difficult for us to arrive on time. (specifically us)
The first sentence makes a universal claim: arriving on time is hard for whoever. The second narrows the subject to nós. A speaker who uses chegar everywhere will sound stilted or vague; a speaker who uses chegarmos when they mean nós will sound like a native. The dedicated page on personal vs regular infinitive walks through the decision rules.
Register: a living feature, not a literary relic
Unlike certain morphological curiosities (the future subjunctive, the pluperfect simple), the personal infinitive is not a formal or literary feature. It is used constantly in everyday European Portuguese speech, in SMS and WhatsApp messages, in television dialogue, and in casual conversation. Skipping it because it sounds "advanced" will make your Portuguese sound foreign. Portuguese children master it naturally by around age four or five; an adult learner needs to put in the reps, but the goal is fluency, not elegance.
Vamos embora antes de começar a chover.
Let's leave before it starts to rain. (generic it — no personal infinitive needed)
Vamos embora antes de os miúdos começarem a chorar.
Let's leave before the kids start crying. (new subject — personal infinitive does the work)
Both are everyday sentences. The second uses the personal infinitive because a new subject (os miúdos) has entered the scene; without the -em ending on começarem, the sentence would be confusing.
A distinctive feature of PT-PT speech
Brazilian Portuguese and European Portuguese both have the personal infinitive, and the forms are the same in both. But European Portuguese leans on it more heavily in speech, especially in constructions like para + personal infinitive, where Brazilian Portuguese sometimes prefers a finite subordinate clause instead. If you are aiming for natural European Portuguese, being comfortable with the personal infinitive is not optional — it is one of the markers that distinguishes a fluent speaker from a hesitant one.
A teaser paradigm: six verbs at a glance
Here are six high-frequency verbs — three regular, three irregular — in the personal infinitive, so you can see the pattern across verb classes.
| Person | falar (reg) | comer (reg) | partir (reg) | ser (irr) | ter (irr) | ir (irr) |
|---|---|---|---|---|---|---|
| eu | falar | comer | partir | ser | ter | ir |
| tu | falares | comeres | partires | seres | teres | ires |
| ele/ela | falar | comer | partir | ser | ter | ir |
| nós | falarmos | comermos | partirmos | sermos | termos | irmos |
| eles/elas | falarem | comerem | partirem | serem | terem | irem |
Notice something unusual: even the wildly irregular ser, ter, ir take the same endings on the same base (the infinitive itself). This is the best news in the whole Portuguese verbal system — the personal infinitive has no irregular stems. Master the endings and you can form the personal infinitive of any verb in the language. The dedicated formation page drills the paradigm, including the one true oddity: pôr keeps its circumflex throughout (pôr, pores, pôr, pormos, porem).
Common Mistakes
❌ Para eu sabermos a verdade, diz-me tudo.
Incorrect — the ending -mos agrees with nós, not eu. Match the ending to the subject.
✅ Para eu saber a verdade, diz-me tudo.
For me to know the truth, tell me everything.
The personal infinitive must agree in person and number with its subject. Eu takes the bare form (no ending); sabermos would be nós.
❌ É importante que chegarmos a horas.
Incorrect — you cannot combine que with a personal infinitive. Pick one structure or the other.
✅ É importante chegarmos a horas.
It's important that we arrive on time. (personal infinitive, no que)
✅ É importante que cheguemos a horas.
It's important that we arrive on time. (que + present subjunctive)
The personal infinitive and que are mutually exclusive. If you have que, the embedded verb must be finite (subjunctive or indicative). If you want a personal infinitive, drop the que.
❌ Quero tu saíres já.
Unusual — volition verbs like querer with a subject change take que + subjunctive, not a personal infinitive.
✅ Quero que saias já.
I want you to leave right now.
The strict volition verbs (querer, desejar, preferir) do not license a bare personal infinitive with a subject change — they require que + subjunctive. This is a boundary learners often cross. The personal infinitive thrives after prepositions and impersonal expressions, but not in the immediate scope of querer, desejar, or preferir. (Note: pedir is different — it readily accepts pedir para + personal infinitive, as in pediu para chegarmos às nove.)
❌ Antes de nós chegar, o filme já tinha começado.
Incorrect — with a subject like nós, inflect the infinitive: chegarmos.
✅ Antes de nós chegarmos, o filme já tinha começado.
Before we arrived, the film had already started.
Once you have written a subject pronoun (nós), the infinitive should be inflected to match. Writing nós chegar is a dead giveaway that the speaker is translating from Spanish.
❌ Ao sairmos nós da sala, todos se levantaram.
Unusual word order — the subject normally follows the inflected infinitive directly, without -mos on both ends.
✅ Ao sairmos da sala, todos se levantaram.
When we left the room, everyone stood up.
✅ Ao nós sairmos da sala, todos se levantaram.
When we left the room, everyone stood up. (with explicit subject pronoun)
If the subject is recoverable from context, you do not need to spell it out. The -mos ending already tells the listener the subject is nós.
Key takeaways
- Portuguese is the only major Romance language with a conjugated infinitive. It agrees with its subject in person and number.
- Endings: (eu) –, (tu) -es, (ele) –, (nós) -mos, (eles) -em. Add them directly to the infinitive, including for irregular verbs.
- Four main uses: after prepositions, as the subject of impersonal expressions, in absolute clauses, and to disambiguate subjects in coordination.
- It is not a formal or literary feature — it is used constantly in everyday speech.
- The personal infinitive and que + subjunctive are competing structures; both are grammatical in many contexts, and choosing between them is a B2 skill.
- You cannot combine que with a personal infinitive. They are mutually exclusive.
Continue to formation to learn the endings in detail, or to personal vs regular infinitive for the decision rules.
Related Topics
- 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 vs Regular Infinitive: When to InflectB1 — The decision rules for choosing between the impersonal (bare) infinitive and the personal (inflected) infinitive — the most consulted page in this set.
- 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.
- Verb Moods: Indicative, Subjunctive, ImperativeA2 — The three main moods and when to use each