Personal Infinitive Use with Different Subjects

In English, we usually say things like "It’s important for us to go." The verb "to go" doesn't change regardless of who is going. In Portuguese, we often prefer to say "É importante irmos." Notice that irmos is the verb ir with a specific ending for "we." This happens because Portuguese loves to specify the subject whenever possible. This grammar point kicks in when the subject of the infinitive is different from the main subject. It also appears after certain prepositions. It’s like a grammar traffic light. It tells the listener exactly which direction the action is heading. Yes, even native speakers mess this up sometimes in casual speech, but using it correctly shows real sophistication. It’s a bit like wearing a tailored suit versus a tracksuit; both work, but one clearly stands out.

1. 1Start with the impersonal infinitive (the basic form of the verb like falar, comer, or ir).
2. 2Add the specific personal infinitive endings to the end of the verb.
3. 3For eu (I), add nothing: falar.
4. 4For tu (you informal), add -es: falares.
5. 5For ele/ela/você (he/she/you formal), add nothing: falar.
6. 6For nós (we), add -mos: falarmos.
7. 7For vós (you plural informal), add -des: falardes.
8. 8For eles/elas/vocês (they/you plural), add -em: falarem.
9. 9Wait, did you notice that? The eu and ele forms look exactly like the base verb. The magic happens with tu, nós, and eles. Also, here is a secret: these endings are the same for AR, ER, and IR verbs. It’s a rare gift from the grammar gods! No need to learn three different tables.

Use it when the subject of the infinitive is clearly expressed or different from the main subject. Imagine you are at a job interview. You might say, "Estou aqui para nós falarmos sobre a vaga" (I am here for us to talk about the opening). Here, the main subject is "I," but the talking is done by "us." Another classic spot is after prepositions like para, sem, por, antes de, depois de, or ao. For example, "Antes de eles chegarem, vamos limpar a sala" (Before they arrive, let's clean the room). It adds a layer of precision that makes your Portuguese sound incredibly smooth. Use it when you want to avoid ambiguity. If you just said "para falar," we might not know if it’s for me, you, or them to talk. The personal infinitive clears that up instantly.

Don't use it when the subject of the infinitive is the same as the main verb and there's no risk of confusion. For example, "Eu quero comer" (I want to eat) is perfect. You don't need to say "Eu quero eu falar." That would just be weird. Also, avoid it in fixed impersonal expressions where no specific person is intended. "É proibido fumar" (Smoking is prohibited) stays impersonal because it applies to everyone. If you're using auxiliary verbs like ir, poder, or querer in a verb chain, keep the second verb impersonal. "Nós podemos sair" (We can leave) is the way to go. Using sairmos there would be grammar overkill. Think of it like salt: essential for the dish, but don't dump the whole shaker in.

The biggest trap is confusing the Personal Infinitive with the Future Subjunctive. For regular verbs, they look identical! Falar, falares, falar, falarmos, falardes, falarem. The difference is the context. The Future Subjunctive is for "if" or "when" situations in the future (e.g., se eu falar). The Personal Infinitive is for general actions, often after prepositions. Another mistake is forgetting the -em for the plural "them" form. People often say para eles falar instead of para eles falarem. It sounds a bit "Tarzan-style" to a native ear. Finally, watch out for irregular verbs. While the Personal Infinitive is almost always regular, the Future Subjunctive of irregulars changes its stem (like tiver from ter). The Personal Infinitive always uses the base infinitive (ter, teres, termos).

Let’s compare the Impersonal vs. Personal Infinitive. Impersonal: "Viver é difícil" (Living is hard). It’s a general statement. Personal: "Para eles viverem aqui, precisam de visto" (For them to live here, they need a visa). Here, we have a specific subject. Now, let’s look at the Infinitive vs. the Subjunctive. Sometimes you can choose. "É bom que vocês estudem" (Subjunctive) vs. "É bom vocês estudarem" (Personal Infinitive). Both mean "It's good that you study." The infinitive version often feels more direct and is very common in spoken Brazilian Portuguese. It’s like choosing between "It is necessary that you leave" and "It’s necessary for you to leave." One is a bit more formal, the other is a bit more practical.