Suppose I want to say:
Maybe your appetite is a sign of returning health.
Fortasse orexis tua sānitātem portendit revertentem.
I'm not sure that revertor carries this metaphor as easily in Latin as "return" can in English. I think restituere would be a stronger, clearer verb, so let's try that—and this will explain my question, which is more general than just how to word one sentence:
Fortasse orexis tua sānitātem restituere portendit.
Fortasse orexis tua sānitātem portendit restituentem.
These both sound wrong to my semi-educated ear. Doesn't restituō mean that its object is being restored, not its subject? I've come across suggestions that Latin allows a "middle voice" with almost as much flexibility as in English—but even in English, "Your health is restoring" sounds a little odd. A typical usage might be rēgem restituere: to restore the king to his throne; rex restituit would require an object: what the king is reinstating.
The infinitive also sounds wrong to me. The idea to be communicated in the sentence is that restoration of health might be in process right now, with no suggestion of completion. I understand the present tense to express that; the infinitive seems less clear. Maybe I'm being led too much by my native English, but a present participle seems ideal here—but present participles can only be active.
How does Latin express this notion of the action of a verb being now in progress, incomplete, without bringing in a separate agent?
Passive voice? But doesn't this suggest that some unnamed external agent is doing the restoration or healing?
Fortasse orexis tua sānitātem restituī portendit.
Fortasse orexis tua tē sānārī portendit.
Fortasse orexis tua portendit ut sānēris.
This seems clumsy:
Fortasse orexis tua sānitātis restitūtiōnem portendit.
Must we choose an intransitive verb? Put in a reflexive agent by analogy with sē movēre? Something completely different?
Fortasse orexis tua sānitātem portendit recrēscēns.
Fortasse orexis tua tē tē sānāre portendit. (??)
Fortasse orexis tua portendit ut tē sānēs?
Fortasse orexis tua significat ut validus fīās dē novō.
Fortasse orexe tuā valēscere sē monstrat.
Fortasse orexe tuā vidēmus tē valēscere.
Quia valēscās famēs augēscit.
By the way, I haven't encountered orexis in any reading; I looked it up after rejecting appetitiō and appetītus as ambiguous without context. Finding a word in a dictionary is often a poor guide to using it properly, so please correct me in the comments if I've got that or anything else wrong, and I'll update the question. I don't want to distract from the main question about verbs.