Introduction
The infinitivo pessoal is a uniquely Portuguese verb form that often puzzles English-speaking learners. It lets verbs agree with a subject even when they appear in an infinitive structure, clarifying who does what. This article explains rules, patterns, and uses with clear Brazilian Portuguese examples to help beginners and intermediate learners master sentences that sound natural and precise.
- What is the personal infinitive?
- Forms and endings of the personal infinitive
- Main contexts for using the personal infinitive
- Forming negative and compound structures
- Pronouns and placement with the personal infinitive
- Comparing personal infinitive and subjunctive
- Practical tips for learners
- Cultural and usage notes
- Common mistakes and how to avoid them
- Examples of clear sentences with translations
- Conclusion
What is the personal infinitive?
The infinitivo pessoal is an infinitive that changes its ending to match the subject. In English, infinitives are invariable: to eat, to speak, to study. In Portuguese, the personal infinitive can have different endings when the subject is explicit or implied, making sentences less ambiguous and often more concise.
Why Portuguese uses the personal infinitive
Portuguese uses the infinitivo pessoal to show who is responsible for the action when verbs follow certain expressions or conjunctions. It replaces the need for an additional clause with a conjugated verb. This is especially helpful with prepositions, after verbs that express desire or obligation, and in comparative or temporal constructions.
Forms and endings of the personal infinitive
The endings for the infinitivo pessoal depend on the verb group (-ar, -er, -ir) and the person (singular/plural). The base infinitive is the first person form without -ar/-er/-ir, then add endings for the personal forms.
Regular verb endings
Here are the typical endings for all verb groups using the verb falar, comer, and abrir as models:
falar / comer / abrir
eu falar-e / comer-e / abrir-e (rare in speech; often omitted and the simple infinitive is used)
tu falar-es / comer-es / abrir-es
ele, ela, você falar / comer / abrir (same as the bare infinitive)
nós falar-mos / comer-mos / abrir-mos
vós falar-des / comer-des / abrir-des (formal or literary; rare in Brazil)
eles, elas, vocês falar-em / comer-em / abrir-em
Note that the third person singular uses the base infinitive without extra endings. This can be confusing because the unmarked infinitive sometimes looks identical to the impersonal form.
Irregularities and spelling changes
Some verbs keep stem changes or irregularities in the personal infinitive. For example, dizer becomes dizer-emos (nós), but the stem change may persist depending on the verb. Verbs with orthographic changes for pronunciation, like chegar (chegar-mos) or conhecer (conhecer-mos), follow spelling rules to keep pronunciation consistent.
Main contexts for using the personal infinitive
The infinitivo pessoal appears in several common structures. Below are the main contexts with clear rules and realistic examples.
1. After prepositions
When a verb follows a preposition and the subject is explicit or different from the main clause, use the infinitivo pessoal. This clarifies who performs the action.
Example with different subjects
Eu quero que tu estudar para a prova. (Incorrect)
Eu quero que tu estude para a prova. (More common but uses subjunctive)
Eu quero tu estudar para a prova. (Colloquial, ambiguous)
Eu quero tu estudares para a prova. (Formal, clear using infinitivo pessoal)
Better and natural alternative using preposition and personal infinitive:
É importante para ti estudares antes do exame. (It is important for you to study before the exam)
2. After verbs of desire, obligation, permission, and suggestion
Verbs like querer, precisar, permitir, mandar can be followed by the personal infinitive to indicate who must perform the action.
Examples:
Eu quero que vocês fazerem o trabalho. (Less common, often subjunctive is used instead)
Eu quero vocês fazerem o trabalho. (Clear personal infinitive use: I want you to do the work)
Ela precisa nós chegar-mos cedo. (Incorrect spacing; correct form: Ela precisa que nós cheguemos — subjunctive — or Ela precisa nós chegarmos cedo for personal infinitive emphasis)
Note: In everyday Brazilian Portuguese, speakers frequently use the subjunctive with que clauses. The infinitivo pessoal is more common after prepositions and in formal registers, but it remains a valid and clear alternative.
3. With conjunctions expressing purpose or time
Conjunctions like para, sem, antes de, depois de, ao, quando often take infinitives. Use the infinitivo pessoal when the subject of the infinitive differs from the main verb or when you want to emphasize the subject.
Examples:
Saí cedo para eles verem o pôr do sol. (I left early so they could see the sunset)
Antes de nós sairmos, precisamos preparar tudo. (Before we leave, we need to prepare everything)
Ao invés de eu esperar, decidi ir embora. (Instead of me waiting, I decided to leave)
4. In comparative structures
Comparisons that use mais, menos, melhor, pior can be followed by a personal infinitive to compare actions performed by different people.
Examples:
É melhor tu falar com ela do que eu falar. (This uses bare infinitives but can be made explicit with personal forms)
É melhor tu falares com ela do que eu falar. (Better for you to talk than me to talk)
Forming negative and compound structures
You can negate the personal infinitive by placing não before it. When using compound tenses with auxiliary verbs like ter or haver plus infinitive, the personal infinitive can also appear, often without agreement, but agreement makes the subject clear.
Negation and auxiliaries
Examples:
Eles decidiram não vir. (They decided not to come — impersonal or same-subject context)
Decidiram não nós vir. (Awkward; better: decidiram que nós não viríamos or decidiram nós não virmos)
Ele teria preferido nós ficarmos e estudar. (He would have preferred us to stay and study)
Pronouns and placement with the personal infinitive
When using clitic pronouns (me, te, se, o, a, nos, lhes) with the personal infinitive, Brazilian Portuguese prefers post-verbal placement in most cases, but placement can vary. In European Portuguese, clitic placement rules are more rigid and literary patterns differ.
Common patterns in Brazilian Portuguese
In Brazilian Portuguese, you often place pronouns after the personal infinitive, especially in spoken language. Use the contracted forms when combined with prepositions.
Examples:
Eles pediram para eu ajudar você. (They asked me to help you)
Eles pediram para eu ajudar-te. (European style; uncommon in Brazil)
É difícil para nós controlarmos nos mesmos em situação de estresse. (Correct: controlarmos-nos is awkward; prefer nos controlarmos)
Comparing personal infinitive and subjunctive
Both the infinitivo pessoal and the subjunctive express non-factual or desired actions, but they are used differently. The subjunctive appears in dependent clauses introduced by que, while the personal infinitive often follows prepositions or appears when subjects differ.
When to use each
Use the subjunctive when the verb is in a finite clause introduced by que and you want to express doubt, desire, or instruction.
Example: Eu quero que você estude mais. (I want you to study more — explicit subjunctive)
Use the personal infinitive when the structure allows an infinitive and you need to mark the subject or prefer a more concise construction.
Example: Eu quero você estudares mais. (More formal or literary; clarifies subject)
Practical tips for learners
Start by recognizing contexts: after prepositions, before differing subjects, and with purpose expressions. Listen to native Brazilian speakers — in conversation, the subjunctive and simplified infinitive forms are common, but understanding the infinitivo pessoal helps with reading and formal writing.
Progressive learning steps
1. Learn the regular endings and practice with common verbs like falar, comer, abrir.
2. Read examples in newspapers or formal writing to see the personal infinitive in action.
3. Use it in writing when you want clarity or formality, especially in prepositional phrases.
4. Compare sentences using subjunctive and personal infinitive to feel the nuance.
Cultural and usage notes
In Brazil, the personal infinitive is less frequent in casual speech; people often use the subjunctive or a subordinate clause with que. However, the infinitivo pessoal is widely used in written Portuguese, legal and academic language, and in contexts where precision is needed. Learning it improves comprehension of newspapers, books, and formal communication.
Remember that regional variation exists: European Portuguese tends to use the personal infinitive more regularly and follows stricter rules for pronoun placement. Brazilian Portuguese is more flexible and conversational, so you will often hear simpler alternatives.
Common mistakes and how to avoid them
1. Using the wrong ending: Check the subject and match it with the correct personal infinitive ending.
2. Confusing with subjunctive: If the sentence has que plus a finite verb, use the subjunctive; if there is a preposition or a different subject, consider the personal infinitive.
3. Ignoring pronoun position: In Brazilian Portuguese, use natural pronoun placement and avoid European clitic order in spoken language.
4. Overusing the form: For everyday conversation, native speakers may prefer simpler structures; use the personal infinitive mainly for clarity and formality.
Examples of clear sentences with translations
Eu espero vocês chegarem antes das oito.
I hope you arrive before eight.
Para nós termos sucesso, precisamos nos empenhar.
For us to succeed, we need to commit ourselves.
É melhor ela falar com o gerente do que eu falar com ele.
It is better for her to speak with the manager than for me to speak with him.
Sem você dizer nada, é difícil entender a situação.
Without you saying anything, it is hard to understand the situation.
Eles decidiram nós esperarmos no carro até a chuva passar.
They decided for us to wait in the car until the rain passes.
Conclusion
The infinitivo pessoal is a powerful tool in Portuguese for indicating who performs an action within an infinitive phrase. Learning its endings, contexts, and differences from the subjunctive will improve your clarity in writing and help you understand formal and written Brazilian Portuguese. Practice reading real sentences, pay attention to prepositions and differing subjects, and gradually incorporate the form where it makes your meaning clearer.
