What can Aes Sedai say about the future?

Question

In the Wheel of Time, according to the First Oath, an Aes Sedai can 'speak no word that is not true'. So what can she say (Foretellings aside) about that notoriously unpredictable realm, the future? (The same question could apply to statements made in the ancient language in Paolini's Inheritance series, if people know that but not WoT.)

If she says, "This will happen", does it mean she has to be certain it will happen, or just that she thinks it will happen, or hopes it will, or thinks it more than 50% likely it will?

Can she say, "We'll be fine" if: a) it's very unlikely, but she's kidded herself into believing it? b) she recognises it's very unlikely, and doesn't believe it, but wants to reassure someone else?

Is there any difference between 'shall' and 'will' in what she can say, i.e. in whether the choice of words implies the speaker's volition? E.g. maybe she can say "You shall do this" meaning "I command you to do this" but not "You will do this" as a statement about the future?

Admittedly this is really more of a philosophical question about truth than an SFF question, but there could be an answer to this in maybe an interview with RJ. And for all you duplicate-question-closers out there, I've looked at this question and although the top answer there does discuss Aes Sedai statements about the future, it's only in the context of statements about what the speaker herself will do, and doesn't answer any of my specific questions above.

Answer 1

The Three Oaths allowed you to say whatever you believed was true even if you could not prove it, as well as to dodge around truth; only words you knew to be a lie would not come off your tongue.

_{"New Spring" (short story), collected in Legends}

Here, the extents of the Three Oaths are stated clearly. Aes Sedai cannot knowingly lie.

Asmodean later criticises this.

"[...] What Moiraine believes to be truth, she tells as truth whether or not it is; one of a thousand weaknesses in those fool Oaths."

_{The Fires Of Heaven, chapter 3, "Pale Shadows"}

The Three Oaths allow an Aes Sedai to say something she believes to be true even if she cannot prove it. She can't knowingly lie.
In other words — and this is my interpretation — if she knows something will be absolutely false, she cannot say it.

So she can say, "we'll be fine" if she has deluded herself the they will be, but she can't say the same by way of reassurance if she knows that they're paddle-less up a river of excrement.

Answer 2

Their constraints seem to be simply that they cannot knowingly lie. For example, they cannot say their dress is blue if it is red. Now pertaining to a future statement, they would not be able to say "I guarantee you that tomorrow you will not die". They could however say "I believe that tomorrow you will not die". We see throughout the books that when talking about the future they usually hedge their statements; Moiraine does this a lot, saying things like 'I believe' or 'should'. We never see them speaking absolutes about the future, as they would be restricted on that, except in the case of prophecy. One example is Rand talking about how he will die, because the prophecy says that he will have his blood spilled at Shayol Ghul. Moiraine says something to the effect of "you may not necessarily have to die", but she never says "you don't have to die" or "you won't die". She gives a very speculative answer based on possibility without a lie.

Basically they will not be allowed to say absolutes about the future, and I'm pretty sure they never do. But that is 14 books' worth of combing every line to prove myself wrong, so I'll believe my truths :D

Answer 3

By the end of the series, it is well established that the First Oath only applies to the speaker's perception of their words. If they think what they say is not "not true", then it is okay.