Once you are comfortable with the basics of the personal infinitive after prepositions and impersonal expressions, you start meeting it in stranger places. Portuguese uses the inflected infinitive in absolute clauses, causative constructions, topicalized sentences, and extracted subject positions — structures that have no clean parallel in English or even in the rest of Romance. This page gathers those advanced uses along with two nuts-and-bolts issues that come up constantly at the C1 level: clitic placement with the personal infinitive, and disambiguating it from the identical-looking future subjunctive forms.
Absolute clauses with the personal infinitive
An absolute clause is a non-finite clause that stands slightly apart from the rest of the sentence, contributing a circumstantial meaning (temporal, conditional, causal). Portuguese uses the personal infinitive in two distinct absolute constructions.
A + personal infinitive = simultaneous/temporal
The preposition a + personal infinitive expresses simultaneity with the main clause: "as X does Y," "while X does Y," "upon X doing Y."
Ao chegarmos ao hotel, percebemos que tínhamos esquecido os passaportes.
When we arrived at the hotel, we realized we'd forgotten the passports.
Ao entrares em casa, fecha a porta.
When you come into the house, close the door.
Ao saírem, apagaram as luzes.
As they left, they turned off the lights.
The ao + [personal infinitive] construction is one of the most frequent at the B2–C1 level. It compresses what would otherwise be a full quando + indicative clause into two words. Note the contraction: a + o = ao, with o being a relic article that has fused into the preposition. You will rarely see a chegarmos without the o in modern EP.
Bare personal infinitive = conditional-temporal absolute
In a more literary register, the bare personal infinitive (without ao) can stand as an absolute conditional-temporal clause. This structure compresses "if/when X happens, Y" into a short, elegant phrase.
Sendo assim, não insisto.
That being so, I won't insist. (literary but current)
A tratares-te bem da saúde, tudo o resto se resolve.
As long as you take care of your health, everything else sorts itself out. (literary)
A sabermos disso antes, teríamos agido de outra forma.
Had we known that earlier, we'd have acted differently. (literary conditional)
Portuguese also has a parallel construction using the gerund plus a subject pronoun — chegando ele, começamos a reunião ("once he arrives, we start the meeting"). The gerund version is actually more common in everyday speech for this kind of temporal/conditional absolute; the bare personal infinitive is reserved for more careful writing. We treat the gerund construction in detail on the gerund page.
Causative and permissive constructions
Portuguese has a distinct family of verbs — mandar, deixar, fazer, obrigar, forçar, permitir, proibir — that takes the infinitive (often personal) as a complement describing the action the subject causes, permits, or prohibits. These are the causative and permissive constructions.
Mandar + personal infinitive = to have someone do
Mandei-os fazerem os trabalhos de casa antes do jantar.
I made them do their homework before dinner.
O professor mandou-nos lermos o livro até sexta-feira.
The teacher told us to read the book by Friday.
The direct object (os, nos) names the person made to do the action, and the personal infinitive (fazerem, lermos) marks that same person in the verb ending. The -em of fazerem agrees with os; the -mos of lermos agrees with nos.
An alternative construction uses a simple infinitive instead: mandei-os fazer is also grammatical, and in some registers more common. The personal infinitive variant (mandei-os fazerem) emphasizes the subject of the embedded verb and feels slightly more literary.
Deixar + personal infinitive = to let someone do
Deixa-os brincarem no jardim até ao jantar.
Let them play in the garden until dinner.
Deixaste-me ficar acordado até tão tarde?
You let me stay up so late?
Não os deixo saírem sozinhos à noite.
I don't let them go out alone at night.
Same pattern: object pronoun + personal infinitive inflected to match. Again, the impersonal infinitive (deixa-os brincar) is also acceptable and is more common in casual speech. Many speakers use them interchangeably.
Fazer + personal infinitive
Fizeram-me acreditar que era verdade.
They made me believe it was true.
Isto faz-nos pensarmos duas vezes antes de decidir.
This makes us think twice before deciding. (personal inf — slightly more literary)
Isto faz-nos pensar duas vezes antes de decidir.
This makes us think twice before deciding. (plain inf — more common)
With fazer, the plain infinitive is far more common than the personal form. You will hear faz-nos pensar, rarely faz-nos pensarmos.
Proibir / permitir + de + personal infinitive
Proibiram-nos de entrarmos na sala.
They forbade us from entering the room.
Permitiu-lhes ficarem mais meia hora.
She allowed them to stay another half hour.
Topicalization: infinitive as sentence topic
The personal infinitive can serve as the subject or topic of a sentence, a use that highlights the action itself and often foregrounds the embedded subject.
Lermos todos juntos é mais divertido.
Reading all together is more fun. (action as subject)
Os alunos estudarem para o exame é essencial.
For the students to study for the exam is essential.
Tu arrependeres-te agora não ajuda ninguém.
You feeling sorry now doesn't help anyone.
In all three sentences, the personal infinitive (with its implicit or explicit subject) is the grammatical subject of the matrix verb (é, ajuda). This is a structure that English handles with gerunds ("reading together is fun") or for X to do Y constructions ("for the students to study is essential"). Portuguese handles it with a personal infinitive.
O importante é estarmos todos aqui.
The important thing is that we're all here. (infinitive as predicate of ser)
O problema é eles não perceberem.
The problem is they don't understand.
These "the X is [infinitive clause]" structures are frequent in EP — they compress what would otherwise be a long que-clause into a tight phrase.
Subject-extraction and fronting
A related pattern: the personal infinitive allows the embedded subject to be extracted (moved out front) in a way that gives prominence to the agent. This happens a lot in focus constructions.
Eles é que precisam de estudarem mais.
They're the ones who need to study more. (cleft focus)
Nós estarmos aqui já é meio caminho andado.
Us being here is already half the battle.
O João, não o queres a saber.
João — you don't want him to know. (topic fronting)
These structures sound very Portuguese. They pack information-structural work (topic, focus, contrast) into the infinitive + subject-position arrangement.
Personal infinitive vs gerund absolutes
A subtle contrast at the advanced level: Portuguese has two ways to build an absolute clause that means roughly "as X does Y" or "with X doing Y." You can use the preposition ao + personal infinitive (temporal simultaneity) or the gerund + subject (simultaneity or condition).
Ao chegarmos, ligámos-te logo.
When we arrived, we called you right away. (ao + personal infinitive)
Chegando nós, ligámos-te logo.
Upon our arrival, we called you right away. (gerund absolute)
The two are almost synonymous. Ao + personal infinitive is neutral, everyday. Gerund + subject (e.g., chegando nós) sounds more literary, compressed, and deliberately terse. You will meet both in written EP, but the ao + infinitive structure is much more common in speech.
Clitic placement with the personal infinitive
The personal infinitive, like any verb form, can take clitic object pronouns (me, te, se, nos, vos, o/a/os/as, lhe/lhes). Where the clitic attaches depends on context, and EP has a more rigorous placement rule than BP.
Default: enclisis (clitic attaches after)
In a neutral, non-subordinate context, the clitic attaches to the personal infinitive with a hyphen, just like with finite forms.
É importante levantares-te cedo amanhã.
It's important that you get up early tomorrow.
Gosto de ouvi-la cantar.
I like to hear her sing. (plain infinitive — same enclisis rule)
Preferimos encontrarmo-nos no café.
We'd rather meet at the café.
The last example shows the classic nós reflexive form: encontrarmo-nos. The final -s of encontrarmos drops before the nos clitic, with a hyphen marking the junction. This is an orthographic rule that catches many learners off guard.
After prepositions: proclisis with certain triggers
Here is the tricky bit. After prepositions that introduce the personal infinitive (para, sem, antes de, depois de), modern EP usage varies. With the preposition para, proclisis (clitic before the verb) is very common:
Deixei a chave na mesa para te lembrares.
I left the key on the table so you'd remember.
Fizeste isso para nos ajudares?
Did you do that to help us?
Saí sem me despedir.
I left without saying goodbye. (plain infinitive)
Saíram sem se despedirem.
They left without saying goodbye. (personal infinitive, proclisis)
You will also hear and read the enclitic version (para lembrares-te, para ajudares-nos, sem despedirem-se), which is grammatical and not rare, but the proclitic form tends to feel more natural in contemporary EP. Both are taught as correct in standard grammars.
Negation and other strong proclisis triggers
If the infinitive clause is negated or contains another proclisis trigger (nunca, só, também), the clitic goes before the verb.
É melhor não lhe dizeres nada.
It's better not to tell him anything.
Preferia nunca me sentires assim tão longe.
I'd rather you never felt so far from me.
Sugeri não nos encontrarmos na próxima semana.
I suggested we not meet next week.
The rule is the same as with any other verb form: negation or a proclisis trigger forces the clitic to the front.
The nós form and pronominal drops
Reflexive or pronominal nós forms of the personal infinitive require an orthographic adjustment. The -mos ending drops its final -s before the clitic nos (or vos for vós speakers):
- encontrarmos
- nos = encontrarmo-nos ("for us to meet each other")
- levantarmos
- nos = levantarmo-nos ("for us to get up")
- vermos
- nos = vermo-nos ("for us to see each other")
É importante respeitarmo-nos uns aos outros.
It's important that we respect each other.
Antes de nos deitarmos, temos de fechar a porta.
Before we go to bed, we have to close the door. (proclitic nos — no hyphen needed because of antes de + nós drop)
The contrast in these two sentences is worth studying. The first uses enclisis (respeitarmo-nos) because nothing triggers proclisis. The second uses proclisis (nos deitarmos) because antes de tends to pull the clitic leftward in modern usage. Both patterns are taught and accepted.
Disambiguating personal infinitive and future subjunctive
For regular verbs, the personal infinitive and the future subjunctive are orthographically identical. This is a well-known oddity of Portuguese: falar, falares, falar, falarmos, falarem is both the personal infinitive paradigm and the future subjunctive paradigm for falar.
| Person | Personal infinitive of falar | Future subjunctive of falar |
|---|---|---|
| eu | falar | falar |
| tu | falares | falares |
| ele / você | falar | falar |
| nós | falarmos | falarmos |
| eles / vocês | falarem | falarem |
The two are distinguished only by context, not form. How do you tell which you are looking at?
The context rule
- Personal infinitive: introduced by a preposition (para, sem, antes de, ao), or after an impersonal expression (é importante, é melhor), or as the subject/topic of a clause.
- Future subjunctive: introduced by a conjunction of time or condition (quando, se, enquanto, assim que, sempre que, conforme) referring to the future.
Compare:
Quando eu chegar a casa, vou descansar.
When I get home, I'll rest. (quando → future subjunctive)
Para eu chegar a casa, preciso de apanhar o comboio.
For me to get home, I need to catch the train. (para → personal infinitive)
Both sentences contain eu chegar. But in the first, chegar is future subjunctive (triggered by quando with future reference); in the second, it is the personal infinitive (triggered by the preposition para). The form is identical; the function is completely different.
Irregular verbs break the tie
For irregular verbs, the two forms diverge, and the ambiguity disappears.
| Verb | Personal infinitive (tu) | Future subjunctive (tu) |
|---|---|---|
| ser | seres | fores |
| ir | ires | fores |
| ter | teres | tiveres |
| estar | estares | estiveres |
| fazer | fazeres | fizeres |
| vir | vires | vieres |
| dizer | dizeres | disseres |
| pôr | pores | puseres |
| trazer | trazeres | trouxeres |
| ver | veres | vires |
Notice the ver / vir overlap: the future subjunctive of ver (to see) is vires — and so is the personal infinitive of vir (to come). These two forms are homographic but belong to different verbs. Context resolves which one is meant.
Quando vires a Joana, dá-lhe um beijo meu.
When you see Joana, give her a kiss from me. (vires = fut subj of ver)
É importante vires à festa.
It's important that you come to the party. (vires = personal inf of vir)
Two identical-looking verbs, two different meanings. The preposition/conjunction tells you which one is which.
Pôr and its compounds in complex constructions
The verb pôr (to put) keeps its circumflex in all personal infinitive forms: pôr, pores, pôr, pormos, porem. Because pôr appears constantly in compound verbs (compor, dispor, propor, supor, impor, depor), you will meet the circumflex repeatedly in advanced texts.
É importante pormos as coisas no sítio certo.
It's important that we put things in the right place.
Antes de comporem a carta, pensem bem.
Before you compose the letter, think carefully.
Propor-se a isso é arrojado.
To propose oneself for that is bold. (pôr as infinitive topic)
The 1sg and 3sg forms (pôr, compor) keep the circumflex to mark the long stressed vowel — a rare case of the personal infinitive preserving a diacritic that disappears in other Portuguese verb forms.
A worked example: three uses in one paragraph
Here is a paragraph that strings together three advanced uses of the personal infinitive:
Ao entrarmos no museu, o guia mandou-nos tirarmos as mochilas. Depois de pormos os casacos no bengaleiro, pudemos começar a visita. Para vermos a exposição com calma, o melhor é passarmos duas horas inteiras lá dentro.
When we entered the museum, the guide told us to take off our backpacks. After we put our coats in the cloakroom, we were able to start the visit. For us to see the exhibition at leisure, the best thing is for us to spend two full hours inside.
The paragraph contains: ao entrarmos (temporal absolute), mandou-nos tirarmos (causative), depois de pormos (prepositional with irregular pôr), para vermos (purpose), passarmos (impersonal expression). Five personal infinitive uses in three sentences — and to a native ear, it reads as perfectly ordinary written prose.
Common Mistakes
❌ Ao eu chegar, liga-me.
Incorrect — 'ao' with explicit subject 'eu' sounds odd; either drop the pronoun or restructure.
✅ Ao chegar, liga-me.
When I arrive, call me. (eu understood from main clause)
✅ Quando chegar, liga-me.
When I arrive, call me. (future subjunctive alternative)
Ao + personal infinitive tends to work best when the subject is clear from context or is explicit in the main clause. Inserting eu into the ao clause itself is awkward.
❌ Mandou-os fazer os trabalhos, mas eles não fizeram.
Correct but neutral — you could also use the personal infinitive for extra agent emphasis.
✅ Mandou-os fazerem os trabalhos, mas eles não fizeram.
He told them to do their work, but they didn't. (personal infinitive — agent emphasis)
With causative verbs, both forms are grammatical; this isn't really a "mistake" but a stylistic choice. The personal infinitive emphasizes the agent; the plain infinitive is more neutral.
❌ Quando vires a Joana (meaning 'when you come to see Joana'), dá-lhe um abraço.
Ambiguous — vires is future subjunctive of ver here, meaning 'when you see her,' not 'when you come.'
✅ Quando vieres ver a Joana, dá-lhe um abraço.
When you come to see Joana, give her a hug. (disambiguated)
The ver / vir homography is a real pitfall. In quando vires a Joana, vires is the future subjunctive of ver — "when you see Joana." If you mean vir (to come), use the explicit periphrasis vieres ver.
❌ É melhor pôrmos a mesa antes de chegarem.
Incorrect spelling — the inflected personal infinitive drops the circumflex.
✅ É melhor pormos a mesa antes de chegarem.
We'd better set the table before they arrive. (1pl personal infinitive of pôr)
The inflected forms of pôr (pores, pormos, porem) do not carry a circumflex, because the stress falls on the ending rather than on the o. Only the bare infinitive pôr (and the 1sg/3sg personal infinitive, which are identical to the bare form) keeps the circumflex.
❌ Para me levantares-te cedo, vais ter de te deitar antes das onze.
Incorrect — double clitic / enclitic-after-proclitic-trigger error.
✅ Para te levantares cedo, vais ter de te deitar antes das onze.
To get up early, you'll have to go to bed before eleven.
If the clitic is already proclitic (te levantares), you do not also attach it enclitically (levantares-te). One or the other.
❌ Deixei-os a fazer os trabalhos sem me chatearem.
Ambiguous — could be interpreted as the object doing the action, but the structure is fine.
✅ Deixei-os a fazerem os trabalhos sem me chatearem.
I left them doing their work without bothering me. (personal infinitive, clear subject)
With a + infinitive in the sense of "doing X," the personal infinitive adds agent clarity. The non-personal form is grammatical but less precise.
Key takeaways
- The personal infinitive reaches into advanced structures: absolute clauses (ao + inf), causative/permissive verbs (mandar, deixar, fazer), subject/topic position, focus and fronting.
- Clitic placement: enclisis is default (levantares-te), but prepositions like para and sem often trigger proclisis in contemporary EP (para te levantares).
- Nós forms drop final -s before the clitic nos: encontrarmo-nos, levantarmo-nos.
- The personal infinitive and future subjunctive are homographic for regular verbs. Context — which trigger introduces the clause — tells you which is meant.
- Irregular verbs break the tie: seres (personal inf) vs fores (fut subj); vires of ver (personal inf) vs vires of vir (fut subj).
- The verb pôr and its compounds keep the circumflex only on the bare form (which is also 1sg/3sg): pôr. Inflected forms (pores, pormos, porem) drop it.
- At the C1 level, the personal infinitive is no longer a special construction — it is a routine tool for compressing finite clauses into elegant non-finite structures.
For the disambiguation between personal infinitive and future subjunctive in more depth, see Future Subjunctive Overview. For the full decision space between infinitive and subjunctive, see Personal Infinitive vs Subjunctive.
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 vs SubjunctiveB2 — Choosing between the inflected infinitive and que + conjuntivo — where the two compete, where one is forced, and what native European Portuguese speakers actually say.
- Personal Infinitive with Impersonal ExpressionsB2 — É importante nós estudarmos vs é importante que nós estudemos — a full treatment of the personal infinitive after é + adjective constructions and related impersonal triggers.
- 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.
- Future Subjunctive OverviewB1 — The futuro do conjuntivo — a living, everyday tense in European Portuguese that marks uncertain future events after temporal, conditional, and relative triggers. Almost extinct in Spanish; thriving in Portuguese.