Advanced Personal Infinitive in Portuguese

In Brief

Portuguese can give an infinitive its own subject and person ending: antes de sairmos means “before we leave.” At an advanced level, this construction also expresses completed action with ter + past participle (depois de termos chegado) and passive meaning with ser + past participle (por serem convidados). It often replaces a longer clause with a finite verb, but the two structures are not always stylistically or semantically identical.

Overview

An infinitive is the basic, unconjugated form of a verb, such as falar “to speak.” Unlike English, Portuguese has a personal infinitive (infinitivo pessoal): an infinitive that can show who performs its action through an ending, an explicit subject, or both. The basic construction is normally introduced around B1; at C1, the challenge is combining it with perfect and passive meaning and choosing it naturally in complex sentences.

This form is especially useful after prepositions such as antes de “before,” depois de “after,” por “because of/for,” para “in order for,” and sem “without.” It lets Portuguese package a subordinate idea—an idea dependent on the main clause—without a fully conjugated finite verb. English commonly uses an -ing form, “for + noun/pronoun + to,” or a complete clause where Portuguese uses a personal infinitive.

The personal infinitive is not simply a substitute for every subjunctive (a verb form used in clauses involving purpose, uncertainty, evaluation, desire, and similar meanings). It is one option when the syntax allows an infinitive, especially after a preposition. Good usage depends on subject clarity, time relationship, emphasis, and register.

How It Works

The personal endings

Regular and irregular infinitives use the same set of personal endings. The dictionary form is retained; endings are added only in the second-person singular and the three plural persons.

Person	falar	Typical subject	English guide
1st singular	falar	eu	for me to speak
2nd singular	falares	tu	for you to speak
3rd singular	falar	ele, ela, você	for him/her/you to speak
1st plural	falarmos	nós	for us to speak
2nd plural	falardes	vós	for you to speak
3rd plural	falarem	eles, elas, vocês	for them/you all to speak

Because first- and third-person singular have no visible ending, context or an explicit subject often identifies the person: sem eu saber “without my knowing”; sem ela saber “without her knowing.” Subject pronouns before the infinitive are subject forms—eu, not me; tu, not te.

The same pattern applies to irregular verbs because their infinitive remains intact: seres, sermos, serem; ires, irmos, irem; teres, termos, terem. Do not build these forms from a present-tense stem.

Choosing between an uninflected and a personal infinitive

A useful starting principle is subject identity:

• If the infinitive's understood subject is the same as the main verb's subject, an uninflected infinitive is often natural: Saí sem dizer nada — “I left without saying anything.”
• If the infinitive has a different or independently stated subject, the personal infinitive is normally preferred: Saí sem eles perceberem — “I left without them noticing.”
• If clarity or contrast matters, Portuguese may mark the person even when context could supply it: Apesar de sermos amigos, discordamos frequentemente — “Although we are friends, we often disagree.”

This is a strong usage guide, not a mechanical law. Some environments favor the personal form because the subject is prominent; others favor the uninflected form because the infinitive is tightly linked to the main verb.

The compound personal infinitive: ter + past participle

To place the infinitive's action before another reference point, inflect ter as a personal infinitive and add a past participle (the verb form used in combinations such as falado, feito, or chegado).

Person	Compound form with falar	Meaning
eu	ter falado	for me to have spoken
tu	teres falado	for you to have spoken
ele/ela/você	ter falado	for him/her/you to have spoken
nós	termos falado	for us to have spoken
vós	terdes falado	for you to have spoken
eles/elas/vocês	terem falado	for them/you all to have spoken

The participle after ter does not agree with the subject: elas disseram ter chegado cedo, not ter chegadas. The personal ending goes on ter.

The simple form and compound form differ in time perspective:

• Agradeço por virem. — “Thank you for coming” or “for being willing to come”; the event is current, future, or viewed without stressing completion.
• Agradeço por terem vindo. — “Thank you for having come”; the visit is presented as already completed.

The passive personal infinitive: ser + past participle

A passive construction presents the subject as receiving the action rather than performing it. Inflect ser and make the participle agree in gender and number with that subject.

Subject	Passive infinitive	English
eu (masculine)	ser convidado	for me to be invited
tu (feminine)	seres convidada	for you to be invited
ela	ser escolhida	for her to be chosen
nós (mixed/masculine)	sermos informados	for us to be informed
elas	serem aprovadas	for them to be approved

This construction has two independent markings: ser marks grammatical person where an ending exists, while the participle marks gender and number. Thus É importante elas serem ouvidas has plural serem and feminine plural ouvidas.

For a completed passive event, combine both layers: personal infinitive of ter + sido + agreeing participle.

• Depois de termos sido avisados, mudámos os planos. — “After we had been warned, we changed the plans.”
• Ela negou ter sido informada. — “She denied having been informed.”

Only ter receives a personal ending. Sido is fixed, while the final passive participle agrees with the passive subject.

Personal infinitive or a finite clause?

Portuguese often offers two ways to express a similar relationship:

Personal infinitive	Finite clause	Main difference
antes de sairmos	antes que saiamos	Infinitive is compact; finite clause explicitly uses the subjunctive.
para eles entenderem	para que eles entendam	Both express purpose; the second can sound more explicit or clause-like.
apesar de estar cansada	embora esteja cansada	Different connector, similar concession; register and rhythm differ.
sem ninguém notar	sem que ninguém note	The finite version can highlight the event as a separate possibility.

Do not delete que from a finite expression and automatically insert an infinitive. The governing connector must support the new structure: antes que becomes antes de; embora is commonly recast as apesar de; para que becomes para.

Examples in Context

Portuguese	English	Note
Depois de termos chegado, ligámos para casa.	After we had arrived, we called home.	Compound form marks arrival as completed first.
Lamento não teres podido ficar.	I’m sorry you couldn’t stay.	Teres podido has a second-person-singular subject.
Eles negaram terem recebido o aviso.	They denied having received the warning.	The marked plural makes the embedded subject explicit.
Apesar de seres jovem, tens muita experiência.	Despite being young, you have a lot of experience.	Seres identifies informal singular tu.
Sem eu saber, mudaram a data da reunião.	Without my knowing, they changed the meeting date.	Explicit eu clarifies the endingless singular form.
Trouxe cópias para todos poderem acompanhar.	I brought copies so everyone could follow along.	The infinitive has its own plural-meaning subject, todos.
Antes de vocês tomarem uma decisão, leiam o contrato.	Before you make a decision, read the contract.	Vocês takes the third-person-plural form.
É importante sermos realistas quanto aos custos.	It is important for us to be realistic about the costs.	Evaluation plus a first-person-plural infinitive.
É impossível serem aprovados sem apresentarem os documentos.	It is impossible for them to be approved without submitting the documents.	Passive serem aprovados and active apresentarem.
Os candidatos esperam ser entrevistados amanhã.	The candidates hope to be interviewed tomorrow.	Uninflected ser is natural because the subject is shared.
Os candidatos agradeceram por terem sido entrevistados.	The candidates expressed thanks for having been interviewed.	Completed passive: terem sido entrevistados.
O relatório foi revisto antes de ser enviado aos clientes.	The report was reviewed before being sent to the clients.	Singular passive infinitive; the understood subject is o relatório.
Para os dados serem comparáveis, temos de usar o mesmo método.	For the data to be comparable, we have to use the same method.	Explicit infinitive subject followed by passive ser.
Mesmo depois de terem sido avisadas, elas continuaram.	Even after having been warned, they continued.	Avisadas agrees with feminine plural elas.

Common Mistakes

Putting the ending on the main verb instead of the auxiliary

• Wrong: depois de ter chegarmos
• Right: depois de termos chegado
• Why: In the compound infinitive, ter carries the personal ending and the main verb is a fixed past participle.

Making a participle agree after active ter

• Wrong: por elas terem chegadas cedo
• Right: por elas terem chegado cedo
• Why: A participle after active ter is invariant. Agreement appears in a passive construction: terem sido convidadas.

Forgetting agreement in the passive

• Wrong: para as propostas serem aprovado
• Right: para as propostas serem aprovadas
• Why: The passive participle agrees with the subject as propostas: feminine and plural.

Using an object pronoun as the infinitive's subject

• Wrong: sem mim saber
• Right: sem eu saber
• Why: Eu performs the action of knowing, so Portuguese uses a subject pronoun. Compare sem mim by itself, where no following verb gives mim a subject role.

Inflecting an infinitive whose subject is tightly shared

• Awkward in neutral usage: Eu tentei resolver eu o problema or eu tentei resolvermos o problema
• Right: Eu tentei resolver o problema.
• Why: After verbs such as tentar, querer, and poder, an infinitive controlled by the same subject is normally uninflected. A plural ending that conflicts with the controller is ungrammatical.

Treating the infinitive as a drop-in replacement for the subjunctive

• Wrong: Antes que sairmos, fechámos as janelas.
• Right: Antes de sairmos, fechámos as janelas.
• Also right: Antes que saíssemos, fechámos as janelas.
• Why: Antes que introduces a finite subjunctive clause; the infinitive construction requires antes de.

Usage Notes

European and Brazilian Portuguese

The grammatical system exists in both major varieties. The most noticeable differences here are often pronouns and surrounding vocabulary rather than the construction itself. Vocês takes third-person-plural forms in both varieties: para vocês fazerem. The vós form (fazerdes) survives in limited regional, religious, literary, or ceremonial contexts and is uncommon in everyday speech.

There is also variation in how strongly speakers prefer an explicitly inflected infinitive when its subject can already be recovered. Formal writing often uses the endings to prevent ambiguity, but piling an explicit noun or pronoun onto every infinitive can sound heavy. Choose clarity rather than maximum marking.

Word order and clarity

An explicit subject normally comes before the infinitive: para os alunos compreenderem, sem eu perceber. Longer phrases may be reorganized for readability, but keep the subject close enough that the reader cannot mistake it for an object of the preceding verb.

With pronouns attached to infinitives, placement differs across varieties and registers. For this topic, first secure the clause structure—subject, auxiliary, participle—before refining clitic placement. For example, antes de nos terem informado means “before they had informed us”: nos is the object, while the plural ending in terem points to an understood plural subject.

Meaning is not always identical

A finite subjunctive clause can make an event feel more independent, hypothetical, or explicitly anchored in tense. A personal infinitive is tenseless in form: its time is inferred from the main clause, a time expression, or the perfect auxiliary ter. Consequently, antes de sairmos can fit several time frames, while antes que saíssemos explicitly places the subordinate verb in the imperfect subjunctive.

Beyond the Basics / Advanced Use

At high levels, the personal infinitive is also a tool for managing information. Compare O diretor pediu para os técnicos verificarem os dados with O diretor pediu que os técnicos verificassem os dados. Both can report the request, but the infinitive version is compact and foregrounds os técnicos beside their task; the finite version presents a fuller reported clause. Context, regional preference, and the style of the document influence which sounds better.

The overt ending can resolve a structural ambiguity. Ouvi os músicos tocar may be understood through the perception-verb construction, “I heard the musicians play.” In a prepositional clause, antes de os músicos tocarem, the plural ending clearly establishes os músicos as the subject of tocar. Advanced writing uses this clarity strategically rather than treating personal endings as decoration.

Be careful with apparent person marking where the subject is not a standard personal pronoun. Collective expressions such as toda a gente are grammatically singular, so para toda a gente entender is expected. By contrast, todos is plural: para todos entenderem. The infinitive agrees with grammatical number, not merely with the idea of “many people.”

Finally, the compound passive can become dense: por alegadamente terem sido mal interpretadas (“for allegedly having been misinterpreted,” referring to feminine plural items). It is grammatical, but a full finite clause may be easier to process. C1 control includes knowing when not to compress: clarity can be more elegant than syntactic complexity.

Practice Tips

1. Build each construction in layers. Start with informar, then make ter informado, ser informado/a, and ter sido informado/a. Finally add personal subjects: termos informado, serem informadas, terem sido informados.
2. Rewrite pairs, not isolated sentences. Convert antes que eles cheguem into antes de eles chegarem, and embora sejamos amigos into apesar de sermos amigos. Check that the connector changes as well as the verb.
3. Mark three things while reading: underline the infinitive's subject, circle the personal ending, and box any agreeing passive participle. This separates person marking from gender/number agreement.

Related Concepts

• Prerequisite: Personal Infinitive — introduces the basic endings and the core choice between personal and uninflected infinitives.