Personal Infinitive: Formation

The personal infinitive has the most generous formation rule in Portuguese: there are no irregular verbs. Every verb in the language, regular or irregular, builds its personal infinitive the same way — by taking the dictionary infinitive and adding a small set of personal endings. Once you know the endings, you can form the personal infinitive of ser, ter, ir, fazer, pôr, dizer, and every other notorious irregular verb without looking anything up.

This page walks through the endings, the paradigm for regular -ar, -er, -ir verbs, irregular verbs (where nothing unusual happens), and the two subtleties worth noting: the circumflex on pôr, and the homography with the future subjunctive.

The endings

The personal infinitive attaches five endings to the full infinitive (not the stem). The first and third person singular forms have no ending — they look identical to the impersonal infinitive. The other three forms add a visible ending.

PersonEnding
eu— (no ending)
tu-es
ele / ela / você— (no ending)
nós-mos
eles / elas / vocês-em

That is the entire formation rule. The endings are the same for all verb classes, all stems, and all irregular verbs. You add them directly to the infinitive as it appears in the dictionary — falar, comer, partir, ser, ter, ir, pôr, dizer, and so on.

Para tu falares bem português, tens de praticar todos os dias.

For you to speak good Portuguese, you have to practise every day.

É bom eles comerem legumes ao almoço.

It's good that they eat vegetables at lunch.

Regular verbs: the full paradigm

Regular verbs come in three classes by the ending of their infinitive: -ar, -er, -ir. The personal infinitive follows the universal pattern for all three.

-ar verbs: falar (to speak)

PersonPersonal infinitive of falar
eufalar
tufalares
ele / ela / vocêfalar
nósfalarmos
eles / elas / vocêsfalarem

É preciso falarmos com o professor antes do exame.

We need to speak with the teacher before the exam.

-er verbs: comer (to eat)

PersonPersonal infinitive of comer
eucomer
tucomeres
ele / ela / vocêcomer
nóscomermos
eles / elas / vocêscomerem

Antes de comeres, lava as mãos.

Before you eat, wash your hands.

-ir verbs: partir (to leave / to break)

PersonPersonal infinitive of partir
eupartir
tupartires
ele / ela / vocêpartir
nóspartirmos
eles / elas / vocêspartirem

Antes de os convidados partirem, vamos tirar uma fotografia.

Before the guests leave, let's take a photo.

Notice the pattern is identical across all three classes — -ar, -er, -ir verbs do not behave differently. The only variation is the vowel in the infinitive itself (-a-, -e-, -i-).

Irregular verbs: the good news

Here is where the personal infinitive rewards you. Verbs that are wildly irregular in every other tense — ser, ter, ir, haver, fazer, dizer — are completely regular in the personal infinitive. They take the same five endings on the same base (the infinitive).

ser (to be)

PersonPersonal infinitive of ser
euser
tuseres
ele / ela / vocêser
nóssermos
eles / elas / vocêsserem

É estranho seres tu a dizer-me isso.

It's strange that it's you telling me this.

Para sermos bons profissionais, temos de ler muito.

For us to be good professionals, we have to read a lot.

ter (to have)

PersonPersonal infinitive of ter
euter
tuteres
ele / ela / vocêter
nóstermos
eles / elas / vocêsterem

É raro teres razão em tudo.

It's rare for you to be right about everything.

Lamento eles terem perdido o comboio.

I'm sorry they missed the train.

ir (to go)

PersonPersonal infinitive of ir
euir
tuires
ele / ela / vocêir
nósirmos
eles / elas / vocêsirem

Antes de irmos embora, temos de falar com o gerente.

Before we leave, we need to speak with the manager.

haver (to have, auxiliary)

PersonPersonal infinitive of haver
euhaver
tuhaveres
ele / ela / vocêhaver
nóshavermos
eles / elas / vocêshaverem

Though haver in its impersonal existential use (há, havia, houve — "there is, there was, there were") almost never needs a personal form, the paradigm exists and surfaces in formal or legal writing.

fazer (to do, to make)

PersonPersonal infinitive of fazer
eufazer
tufazeres
ele / ela / vocêfazer
nósfazermos
eles / elas / vocêsfazerem

É difícil fazermos tudo no mesmo dia.

It's difficult for us to do everything on the same day.

dizer (to say)

PersonPersonal infinitive of dizer
eudizer
tudizeres
ele / ela / vocêdizer
nósdizermos
eles / elas / vocêsdizerem

Sem tu dizeres nada, já sabia que tinhas gostado.

Without your saying anything, I already knew you'd liked it.

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Say this out loud: "the personal infinitive has no irregular stems." Then say it again. After decades of learning messy Portuguese conjugations, you will not believe there is a tense with literally zero exceptions. But there is, and this is it. Every verb in the language takes these five endings on its dictionary form.

The one real subtlety: pôr

The verb pôr ("to put") has a circumflex accent on its infinitive — this is the one place in modern Portuguese orthography where the infinitive carries an accent. The circumflex is there to mark pôr as distinct from the preposition por ("by, for, through"). In the personal infinitive, the circumflex is kept whenever no ending is added, and dropped whenever an ending follows.

PersonPersonal infinitive of pôr
eupôr
tupores
ele / ela / vocêpôr
nóspormos
eles / elas / vocêsporem

The rule: pôr has the circumflex when the word ends there. Once a vowel-initial ending follows (-es, -mos, -em), the circumflex disappears, because the accent was only needed to distinguish the solitary form pôr from por.

Antes de pôr a mesa, lembra-te de lavar as mãos.

Before setting the table, remember to wash your hands. (impersonal — no ending)

Antes de pores a mesa, lembra-te de lavar as mãos.

Before you set the table, remember to wash your hands. (personal, tu — no circumflex)

Para pormos tudo em ordem, precisamos de uma hora.

For us to put everything in order, we need an hour.

This same pattern — circumflex only on the bare form — applies to all verbs derived from pôr: compor, propor, opor, dispor, supor, repor. In the personal infinitive they behave like pôr: compores, compormos, comporem; propores, propormos, proporem; and so on, with no circumflex on the inflected forms because the ending provides the phonological anchor.

💡
This is the only real orthographic quirk in the whole personal-infinitive system. Everywhere else, "add the ending to the infinitive" is literally all you need to do. Even for pôr, you simply drop the accent once the ending is in place — no other surgery is required.

Pronominal verbs: clitic attachment

Pronominal (reflexive and object-pronoun) verbs behave just like any other verb in the personal infinitive. The clitic pronoun attaches to the inflected form, and agrees with the subject:

PersonPersonal infinitive of levantar-se
eulevantar-me
tulevantares-te
ele / ela / vocêlevantar-se
nóslevantarmo-nos
eles / elas / vocêslevantarem-se

Note the 1pl form: levantarmo-nos. When the ending -mos meets the clitic nos, the final -s of -mos drops (a general rule for nós forms combining with -nos). This is not specific to the personal infinitive; it happens with any verb form ending in -mos followed by the clitic nos.

É importante levantarmo-nos cedo amanhã.

It's important that we get up early tomorrow.

Depois de se levantarem, os miúdos foram para a escola.

After getting up, the kids went to school.

The homography with the future subjunctive

A feature of Portuguese morphology that surprises learners: for regular verbs, the personal infinitive is identical to the future subjunctive. Compare:

PersonPersonal infinitive of falarFuture subjunctive of falar
eufalarfalar
tufalaresfalares
ele / elafalarfalar
nósfalarmosfalarmos
eles / elasfalaremfalarem

For regular verbs, the two paradigms are 100% identical. Context alone tells you which one a speaker means. This is almost never a problem for comprehension — the constructions that trigger each are completely different:

  • The personal infinitive appears after prepositions (para, sem, antes de...), after impersonal expressions (é importante...), and in a few other bounded contexts.
  • The future subjunctive appears after conjunctions of future time or condition (quando, se, logo que, assim que, enquanto...).

Quando eles chegarem, avisa-me.

When they arrive, let me know. (future subjunctive after quando)

Para eles chegarem a tempo, têm de sair já.

For them to arrive on time, they have to leave now. (personal infinitive after para)

Same form, different paradigm — the trigger word tells you which.

For irregular verbs, the two paradigms diverge. This is where the homography breaks down, because the future subjunctive uses the irregular preterite stem, while the personal infinitive keeps the regular infinitive base. Compare ser:

PersonPersonal infinitive of serFuture subjunctive of ser
euserfor
tuseresfores
ele / elaserfor
nóssermosformos
eles / elasseremforem

Quando formos a Lisboa, visitamos o teu primo.

When we go to Lisbon, we'll visit your cousin. (future subjunctive)

É importante sermos honestos com os nossos amigos.

It's important that we be honest with our friends. (personal infinitive)

For irregular verbs like ser, ter, ir, fazer, dizer, pôr, the personal infinitive and the future subjunctive look nothing alike. See future subjunctive regular forms and future subjunctive irregular forms for the future subjunctive paradigm.

A one-page reference: high-frequency verbs

For quick reference, here are ten high-frequency verbs in full personal-infinitive paradigms.

Infinitiveeutuelenóseles
falarfalarfalaresfalarfalarmosfalarem
comercomercomerescomercomermoscomerem
partirpartirpartirespartirpartirmospartirem
serserseressersermosserem
estarestarestaresestarestarmosestarem
terterterestertermosterem
iririresirirmosirem
fazerfazerfazeresfazerfazermosfazerem
dizerdizerdizeresdizerdizermosdizerem
pôrpôrporespôrpormosporem

Internalize this table and you can form the personal infinitive of any verb in the language.

Common Mistakes

❌ para nós falar com ele

Incorrect — with the subject nós, the infinitive must be inflected.

✅ para nós falarmos com ele

for us to speak with him

If you write the subject pronoun (nós, tu, eles), you must also inflect the infinitive to match. Leaving the infinitive bare with an explicit non-default subject is ungrammatical.

❌ antes de pôres a mesa

Incorrect — the circumflex drops when a personal ending is added to pôr.

✅ antes de pores a mesa

before you set the table

The circumflex on pôr only exists when the word stands alone. Once an ending follows, the accent is redundant and must be dropped. Pores, pormos, porem — all unaccented.

❌ é importante eles seriem honestos

Incorrect — the personal infinitive of ser is serem, not seriem. No stem change.

✅ é importante eles serem honestos

it's important that they be honest

Do not import irregular stems from other tenses. The personal infinitive uses the dictionary infinitive (ser) plus the ending (-em) — nothing more.

⚠ para tu vires cedo

Looks ambiguous: vires is both the personal infinitive of vir ('to come') and the future subjunctive of ver ('to see'). The trigger resolves it.

✅ Para tu vires cedo, apanha o comboio das sete.

For you to come early, take the seven o'clock train. (personal infinitive of vir — triggered by para)

✅ Quando tu vires o sinal, avisa-me.

When you see the sign, let me know. (future subjunctive of ver — triggered by quando)

Both sentences are correct — this is not a true mistake but a common source of confusion. The form vires is both the personal infinitive of vir ("to come") and the future subjunctive of ver ("to see"). Context always disambiguates: para pulls for the personal-infinitive reading of vir, while quando pulls for the future-subjunctive reading of ver.

❌ para nós levantar-nos cedo

Incorrect — with the clitic nos attached, the -s of -mos drops: levantarmo-nos.

✅ para nós levantarmo-nos cedo

for us to get up early

When the -mos ending meets the clitic nos, the final -s of the ending disappears. This is a general rule of Portuguese phonology, not specific to the personal infinitive.

Key takeaways

  • Endings: (eu) –, (tu) -es, (ele) –, (nós) -mos, (eles) -em. Attach them to the infinitive.
  • There are no irregular verbs in the personal infinitive. Ser, ter, ir, fazer, dizer all take regular endings on their regular infinitive bases.
  • Pôr keeps its circumflex only when no ending is added: pôr, pores, pôr, pormos, porem.
  • For regular verbs, the personal infinitive is identical to the future subjunctive. Context (the trigger word) tells you which one is meant.
  • For irregular verbs, the personal infinitive and the future subjunctive diverge — the future subjunctive uses the preterite stem (for, tiver, fizer), the personal infinitive keeps the infinitive base (ser, ter, fazer).
  • Clitic pronouns attach to the end of the inflected infinitive; the -s of -mos drops before nos.

Next: when to use the personal infinitive versus the regular infinitive — the decision rules.

Related Topics

  • Personal Infinitive: OverviewB1The 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 vs Regular Infinitive: When to InflectB1The decision rules for choosing between the impersonal (bare) infinitive and the personal (inflected) infinitive — the most consulted page in this set.
  • Personal Infinitive After PrepositionsB1The 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 SubjectB2Using 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.
  • Regular Future Subjunctive FormsB1How to build the future subjunctive from any regular verb — take the 3pl preterite, drop -am, add the endings. Full paradigms for -ar, -er, and -ir verbs, plus the remarkable homograph relationship with the personal infinitive.
  • Irregular Future Subjunctive FormsB1The handful of Portuguese verbs whose future subjunctive is built from an irregular preterite stem — ser/ir, ter, estar, poder, querer, saber, fazer, dizer, trazer, vir, ver, pôr, dar, haver — with full paradigms and use in everyday sentences.