Breakdown of Acho que eles precisam de paciência até revelarem a verdade.
eles
they (m)
precisar de
to need
a paciência
the patience
a verdade
the truth
Questions & Answers about Acho que eles precisam de paciência até revelarem a verdade.
Why do we use the Personal Infinitive (revelarem) here instead of the Subjunctive?
Because the sentence uses the preposition até on its own, which must be followed by an infinitive. If we wanted to use the subjunctive, we would have to use the conjunction phrase até que to say até que revelem. Both options are perfectly correct, but até plus the Personal Infinitive is often preferred for being slightly more concise.
Since the subject (eles) is the same for both verbs, shouldn't we use the uninflected infinitive (até revelar)?
When the subject is exactly the same in both clauses, the uninflected infinitive is grammatically allowed. However, native speakers frequently choose the Personal Infinitive (revelarem) for plural subjects to make the reference crystal clear and to make the spoken sentence flow better.
Why does Acho que take the present indicative (precisam) rather than the subjunctive?
In Portuguese, the affirmative Acho que expresses an opinion that the speaker considers to be a fact, so it takes the indicative. You would only use the subjunctive if the phrase introduced doubt, which typically happens in the negative form: Não acho que eles precisem.
As a quick refresher, why is de used after precisam?