Personal Infinitive in Portuguese

In Brief

Portuguese can add person endings to an infinitive: estudar (“to study”) becomes estudares (“for you to study”), estudarmos (“for us to study”), or estudarem (“for them to study”). Use this personal infinitive when the infinitive has a stated or clearly distinct subject, especially after para, antes de, depois de, sem, and impersonal expressions: É importante estudarmos (“It is important for us to study”).

Overview

An infinitive is the basic verb form—the form translated with “to” in to speak, to eat, and to leave: falar, comer, partir. English keeps that form unchanged regardless of the person doing the action. Portuguese can do the same, but it can also mark the infinitive for person (who performs the action) and number (singular or plural). This marked form is called the infinitivo pessoal.

The personal infinitive lets Portuguese fit a subject into a compact subordinate clause (a smaller clause that depends on another part of the sentence). Compare antes de sair (“before leaving”) with antes de saíres (“before you leave”). The ending removes uncertainty about who leaves without requiring a finite clause—a clause whose verb carries tense—such as antes que saias.

This is introduced around B1 because the forms themselves are regular, but choosing between a plain infinitive, a personal infinitive, and the subjunctive (a verb form often used for wishes, uncertainty, or dependent events) requires attention to meaning. The construction is productive in both European and Brazilian Portuguese, in speech as well as writing.

How It Works

Formation

Keep the complete infinitive, including its final -r, and add the endings below. All three verb classes use the same endings.

Person	Ending	falar	comer	partir
eu (I)	—	falar	comer	partir
tu (you, singular informal)	-es	falares	comeres	partires
ele / ela / você (he / she / you)	—	falar	comer	partir
nós (we)	-mos	falarmos	comermos	partirmos
vós (you, plural)	-des	falardes	comerdes	partirdes
eles / elas / vocês (they / you, plural)	-em	falarem	comerem	partirem

The first- and third-person singular have no visible ending. Para eu falar and para ela falar are personal in meaning even though falar looks exactly like the uninflected infinitive. The subject pronoun or the context identifies the person.

The form is unusually regular. Even verbs with irregular finite forms normally use the full infinitive as their base:

Infinitive	tu	nós	eles/elas
ser (to be)	seres	sermos	serem
ter (to have)	teres	termos	terem
ir (to go)	ires	irmos	irem
fazer (to do/make)	fazeres	fazermos	fazerem
pôr (to put)	pores	pormos	porem

Do not build these forms from present-tense stems: somos does not produce somos as a personal infinitive; the correct form is sermos.

The core choice: whose action is it?

The strongest reason to use the personal infinitive is that its understood subject differs from the subject of the main verb:

• Saí sem dizer nada. — “I left without saying anything.” The same person left and said nothing, so plain dizer is natural.
• Saí sem eles dizerem nada. — “I left without them saying anything.” The infinitive has its own subject, eles, so dizerem marks it.

An explicit subject strongly favors the personal form: para eu fazer, por tu chegares cedo, sem nós sabermos. When the ending already identifies the subject, the pronoun can be omitted: É melhor irmos agora (“We had better go now”).

Common environments

The construction often follows a preposition or prepositional expression:

Pattern	Typical meaning	Example
para + personal infinitive	purpose, intended result	Trouxe isto para vocês verem.
antes de + personal infinitive	earlier event	Liga-me antes de saíres.
depois de + personal infinitive	later event	Descansámos depois de chegarmos.
sem + personal infinitive	absent action	Foram embora sem se despedirem.
por + personal infinitive	cause or reason	Obrigado por teres vindo.
apesar de + personal infinitive	concession	Apesar de estar cansada, ela continuou.

It also occurs after impersonal expressions—expressions such as “it is important” that do not name an actor in the main clause:

• É importante beber água. — a general statement: “It is important to drink water.”
• É importante bebermos água. — specifically about us: “It is important for us to drink water.”
• É importante que bebamos água. — a finite subjunctive clause: “It is important that we drink water.”

Personal infinitive or subjunctive?

Portuguese often has two possible structures, but they are not mechanically interchangeable.

Personal infinitive	Finite clause	Practical difference
para eles entenderem	para que eles entendam	Both can mean “so that they understand”; the infinitive is more compact.
antes de saíres	antes que saias	Both refer to your leaving; the connector changes with the structure.
É importante estudarmos.	É importante que estudemos.	Both identify “us”; the second explicitly uses the present subjunctive.

Use de before an infinitive after antes and depois: antes de saíres. Use que before a finite subjunctive: antes que saias. Do not combine the two frames.

Pronouns as subjects

Because eu, tu, nós, and so on are the subject of the infinitive, use subject forms:

• Isto é para eu ler. — “This is for me to read.”
• Sem tu saberes, seria impossível. — “Without you knowing, it would be impossible.”

English “for me to…” can tempt learners to use mim. Portuguese uses mim after a preposition when it is not the subject (Isto é para mim), but eu when that person performs the infinitive (Isto é para eu ler).

Examples in Context

Portuguese	English	Note
É importante estudarmos todos os dias.	It is important for us to study every day.	-mos identifies “us.”
Antes de saíres, fecha as janelas.	Before you leave, close the windows.	tu is shown by -es.
Trouxe um mapa para eles entenderem o percurso.	I brought a map so that they could understand the route.	Explicit third-person plural subject.
Isto é para eu fazer hoje?	Is this for me to do today?	Subject eu, not mim.
Obrigado por teres vindo tão cedo.	Thank you for coming so early.	Compound form referring to tu.
Depois de termos comido, fomos dar um passeio.	After we had eaten, we went for a walk.	Completed action with termos + participle.
Ela saiu sem os colegas perceberem.	She left without her colleagues noticing.	Main and infinitive subjects differ.
É melhor irmos de comboio.	We had better go by train.	The ending makes nós unnecessary.
O professor pediu para abrirmos o livro.	The teacher asked us to open the book.	-mos identifies the requested actors.
Apesar de seres novo aqui, conheces toda a gente.	Although you are new here, you know everyone.	apesar de + seres.
Eles ficaram contentes por terem sido convidados.	They were pleased to have been invited.	Compound passive personal infinitive.
Para não nos atrasarmos, saímos às sete.	So that we would not be late, we left at seven.	Reflexive verb agrees with nós.

Common Mistakes

Removing the infinitive’s -r

• Wrong: É importante estudamos mais.
• Right: É importante estudarmos mais.
• Why: Add -mos to the complete infinitive estudar: estudar + mos → estudarmos. Estudamos is a finite present or past form, not a personal infinitive.

Using an object pronoun as the subject

• Wrong: Este relatório é para mim corrigir.
• Right: Este relatório é para eu corrigir.
• Why: The person after para performs corrigir, so Portuguese requires the subject pronoun eu. Use para mim only when no following action has mim as its subject.

Leaving a plural infinitive unmarked when clarity requires it

• Unclear/nonstandard for the intended meaning: Ela esperou os filhos chegar.
• Clear: Ela esperou os filhos chegarem.
• Why: Os filhos is plural and performs chegar. The ending -em makes that relationship explicit.

Inflecting every infinitive in a verb chain

• Wrong: Nós queremos irmos cedo.
• Right: Nós queremos ir cedo.
• Why: After a verb such as querer, poder, or dever, a following infinitive with the same subject normally stays uninflected: queremos ir, podemos entrar, devemos sair.

Mixing infinitive and subjunctive connectors

• Wrong: Antes que saíres, avisa-me.
• Right: Antes de saíres, avisa-me.
• Also right: Antes que saias, avisa-me.
• Why: Use antes de with an infinitive and antes que with a finite subjunctive verb.

Treating the endings like tense endings

• Wrong idea: termos comido means “we eat now.”
• Right interpretation: Depois de termos comido... means “After we had eaten...” or “After having eaten....”
• Why: The personal ending marks the subject, not time. Time comes from context or from a compound form such as ter + past participle.

Usage Notes

The personal infinitive belongs to standard Portuguese throughout the Portuguese-speaking world. How often speakers choose it instead of a finite clause varies with region, register, rhythm, and the surrounding expression. A sentence with the subjunctive may sound more explicit, while the infinitive often sounds compact; neither pattern is automatically more formal.

The form is not compulsory every time its logical subject can be identified. Portuguese usage allows choices, especially when the subject is recoverable from context. A useful learner rule is: inflect it when a separate subject is stated, when the ending prevents ambiguity, or when a conventional expression such as é melhor irmos naturally highlights the person. Avoid inflecting a tightly connected infinitive that simply completes a modal or similar verb with the same subject: podemos sair, not normally podemos sairmos.

The vós forms in -des—falardes, comerdes, partirdes—are grammatically regular but uncommon in everyday Brazilian Portuguese and in much modern European conversation. They still appear where vós itself is used, including some regional, religious, ceremonial, or literary contexts. Everyday plural address generally uses vocês with the third-person plural form: para vocês fazerem.

With unstressed object or reflexive pronouns, placement differs across varieties and sentence patterns. Learn common expressions as units—para nos encontrarmos, sem se despedirem, antes de te deitares—rather than trying to derive all pronoun-placement rules from the infinitive alone.

Beyond the Basics / Advanced Use

The compound personal infinitive

To place the infinitive’s event earlier than another event, inflect ter and add a past participle (the verb form used in combinations such as “have eaten”):

Person	Form with comer	Meaning
eu / ele / ela / você	ter comido	to have eaten
tu	teres comido	for you to have eaten
nós	termos comido	for us to have eaten
vós	terdes comido	for you to have eaten
eles / elas / vocês	terem comido	for them to have eaten

The participle stays unchanged after ter: termos chegado, terem escrito, teres feito. This construction is especially useful after depois de, por, sem, and apesar de: Ela pediu desculpa por ter chegado tarde; Eles negaram terem recebido a mensagem.

Passive forms

A personal infinitive can also be passive. The passive voice presents the subject as receiving the action rather than doing it. Inflect ser and use a participle that agrees with that subject:

• Os candidatos esperam ser chamados. — “The candidates hope to be called.”
• É possível elas serem escolhidas. — “It is possible for them to be chosen.”
• Depois de terem sido aprovadas, receberam os certificados. — “After they had been approved, they received the certificates.”

Here serem identifies the plural subject, while escolhidas also agrees with the feminine plural elas. The last example combines the compound and passive patterns: terem sido aprovadas.

Style and interpretation

Advanced writing uses the personal infinitive to compress information that English often expands into a “that” clause. This can make long Portuguese sentences elegant, but too many nested infinitives can obscure who does what. If the subject or time relationship becomes difficult to recover, a finite clause with que may be clearer.

Some constructions permit both an uninflected and an inflected infinitive with a subtle change of focus rather than a simple right-or-wrong contrast. The uninflected form presents the action more generally; the inflected form foregrounds its subject. At this level, notice which version native writers choose before trying to apply a rigid universal rule.

Practice Tips

1. Transform one sentence across persons. Start with É importante estudar and produce É importante eu estudar, tu estudares, nós estudarmos, and eles estudarem. This highlights the two forms with no visible ending as well as the marked forms.
2. Pair same-subject and different-subject sentences. Compare Saí sem dizer nada with Saí sem eles dizerem nada. Asking “Who performs the infinitive?” is more useful than memorizing a list of triggers.
3. Collect preposition chunks. Make short cards with antes de saíres, para fazermos, sem saberem, and por teres vindo. Include a full sentence so that person and meaning remain clear.

Related Concepts

• Prerequisite: Regular -AR Verbs — provides a foundation for recognizing Portuguese infinitives and verb structure.
• Next step: Personal Infinitive — Advanced — develops compound, passive, and stylistically complex uses in greater depth.