Personal Infinitive in Portuguese: What Is It and When to Use It

The so-called personal infinitive is unique to Portuguese, and we use it a lot.  Because there is no parallel in other languages, it is no wonder that learners of Portuguese often struggle to wrap their heads around it.

For starters, we use the Portuguese personal infinitive in a few impersonal structures as well as in subordinate clauses of different kinds such as concessive, final, and conditional clauses.

Another related question is: what’s the difference between personal and impersonal infinitive (the “normal” infinitive)?

Well, the Portuguese personal infinitive is a conjugated version of the impersonal infinitive. While the latter only represents the conceptual idea of the verb (dissociated from any tense, mood, or person), the former, through its conjugated verb forms, unveils the person that the verb is referring to. Put another way, the personal infinitive makes it more personal and less abstract.

Let’s dive right into its usage.

• Conjugation
• When to use it
  • Impersonal structures
  • Concessive clauses
  • Time clauses
  • Conditional clauses
  • Completive clauses
  • Causal clauses
  • Final clauses

Conjugating the personal infinitive in Portuguese

It is easy to conjugate the personal infinitive. You take the “normal” infinitive form – the impersonal infinitive – and add a few endings to some of the persons, namely the second person singular and every person plural  (added endings marked in bold in the tables below). 

These endings are always the same regardless of the conjugation group (-ar, -er, -ir), or if the verbs are regular or irregular. No exceptions.

Let’s look at 3 regular verbs, one for each conjugation group:

Note! For regular verbs, the verb forms of the personal infinitive happen to be the same as the future subjunctive. That doesn’t apply to irregular verbs.

And here are 3 irregular verbs with the exact same conjugation pattern of above:

When to use the personal infinitive in Portuguese

For the most part, the personal infinitive in Portuguese is used in complex sentences and is normally placed inside the dependent clause right after a linking word or expression. In this section, I will guide you through several such structures and with concrete examples. 

A couple of things before we start.

As we go through the example rundown below, you will realize that we use the personal infinitive in structures where we often also use the present subjunctive*. 

In that sense, they are closely related and whether we use one or the other depends on the linking expression being used. For instance,  the use of the present subjunctive is strongly associated with the linking word que.

* Learn more about the present subjunctive in Portuguese: Present Subjunctive in Portuguese: How and When to Use It.

Also, since only the second person singular + all persons plural verb forms (tu, nós, vocês, eles/elas) are the ones varying between the personal and impersonal infinitive, I will, for the sake of clarity, stick to these throughout the example rundown. 

Impersonal structures

We often use the personal infinitive in the following impersonal structure: 

 é + adjective + personal infinitive

Here’re a couple of examples: 

Note that we use the present subjunctive* if we add que before the verb: 

*Click here for more examples.

Concessive clauses 

We use the personal infinitive in concessive clauses* when they are introduced by the linking expression apesar de:  

* Concessive clauses express an idea that is in opposition to the main clause. In English, concessives clauses are often introduced with the linking words “although”, “even though”, or “despite the fact”, among others. 

Note that we are likely to use the present subjunctive* when we use other linking expressions such as mesmo que, embora or ainda que: 

* Click here for more examples.

Time clauses

We use the personal infinitive in time clauses*, especially when these are introduced by linking expressions such as até,  antes de, or depois de:

* In English, time clauses are often introduced by  linking expressions such as as soon as, before, or until, among others. 

Note that we use the present subjunctive* when we use other linking expressions such as logo que, até que or antes que:

* Click here for more examples.

Conditional clauses

We use the personal infinite in conditional clauses*, especially when they are introduced by the linking word sem:

* Conditional clauses express contingency. In English, conditional clauses are often introduced by if, in case, and unless, among others.

Note that we use the present subjunctive* in the presence of the linking expressions sem que, desde que, or a não ser que, among others: 

* Click here for more examples.

Completive clauses 

We often use the personal infinitive in completive clauses*. This is definitely the case for sentences where the subject of the main clause is different to the subject of the dependent clause: 

* Completive clauses are often the direct object of a verb such as think, believe, see,  ask, among others. They complete the idea/action of the verb in the main clause. They are often introduced by the linking word that, but also by to or even a present participle (the -ing verb form).

Note that we use a present tense (either in the indicative or subjunctive mood) when we use the linking word que before the verb:

Now, we might use the impersonal infinitive* when the subject of both the main and dependent clauses are the same:

* Although grammarians normally advocate for the impersonal indicative (when the subject is the same in both clauses), in practice, native speakers often use the personal and impersonal infinitives interchangeably. So, the sentence Vocês parecem não quererem vir connosco probably wouldn’t hurt anyone’ s ears.

Here’re a few more examples of completive clauses where the personal infinitive follows the linking words de, para, and em:

Causal clauses

We use the personal infinite in causal clauses*, especially those introduced by linking expressions such as por, dado, and visto:

* Causal clauses offer an explanation for what’s stated in the main clause.  In English, causal clauses are often introduced by linking expressions such as because, since, inasmuch as or as, among others.

Note that we use the present or past simple in the presence of the linking words porque or pois:

Final clauses

And there’s nothing more suitable than final clauses to conclude this usage rundown!

We use the personal infinite in final clauses*, especially those introduced by linking expressions such as  para and a fim de:

* Final clauses express intention or purpose.  In English, final clauses are often introduced by linking words such as to, in order to, or so that.

Note that we use the present subjunctive* if we add the word que to the  linking expressions para and a fim de: 

* Click here for more examples

Here’re more examples of sentences where the main and dependent clauses each have their own subject:

As it is the case with with completive clauses (see above), we might use the impersonal infinitive* when both the main and dependent clauses share the same subject:

* Again, in these cases, native speakers seem to use the personal and impersonal indicative interchangeably. Thus, the same sentence using the personal infinitive –  Eles fizeram tudo para (eles) conseguirem o que queriam – sounds fine to my ears as well.