On rare occasions, linguists have the pleasure of seeing the larger world realize that language matters. It’s not “just words” or “only semantics” — the choices a speaker makes have real social and political consequences.

One such occasion was June 8, when former FBI director James Comey testified before the Senate about his conversation with President Trump regarding Michael Flynn, the recently fired national security advisor.

According to Comey, the president asked everyone else in the Oval Office to leave, and then remarked that Flynn was a good man, despite the misbehaviors that got him fired, and he didn’t deserve to be subjected to a criminal investigation. “I hope,” said the president to Comey, “you can let this go.”

The operative word here, as we all know, is hope. Just what was the president telling Comey — and even more important, what wasn’t he telling him? Did either of the participants in the conversation know for sure? Can any of us outsiders know for sure?

No to all of the above, and here’s why.

People tend to think that the meaning and intention of what they say and what is said to them is clear and unambiguous; an ordinary communication has but one form, one meaning, and one purpose. Sometimes this is in fact the case, particularly if all participants (and analysts) agree on both the explicit form of the communication and the complete context in which it was uttered, including the power and intimacy relationships between participants, the purpose of the utterance, and the presence of any metamessage (defined by Deborah Tannen in a Washington Post op-ed as “what it means to say those words in that way in that context”). If all parties agree on all of the above, it is likely that there will be no ambiguity in the message.

But what can constitute a metamessage? Is there any way to know that everyone agrees on it? In the Trump-Comey case, there’s a lot of disagreement about whether there is a metamessage concealed in “hope,” and if so, what it is. There is ambiguity about the ambiguity. In cases like this, language becomes less a means of achieving understanding than a minefield.

For over half a century, these dangerous linguistic moments have been given a lot of attention by pragmaticists, those linguists and philosophers of language concerned with the relationships between the explicit linguistic form of an utterance and its interactive function or purpose. One of the foundational figures of the field, the British analytic philosopher J.L. Austin, discussed in his posthumous work How to Do Things with Words the complex connections between the locution, meaning the words themselves, and the illocutionary force, or what the speaker meant to convey with the words: “Whether,” said Austin, “certain words (a certain locution) had the force of a question, or ought to have been taken as an estimate and so on [italics his].”

Take the famous example of “The cat is on the mat.” One way of intending and understanding that utterance is literal: an assertion about where the cat is, and no more. That is pretty harmless and (to a pragmaticist) pretty uninteresting. But the same phrase could also be used for other purposes, under more complex contextual circumstances. Suppose that in the past the speaker has complained to the hearer that the hearer’s cat was on the speaker’s mat, no doubt shedding on it. That utterance, in the same exact form, may be intended, and may have the illocutionary force of, a directive: the speaker’s instruction to the hearer to get their cat off the mat. That might, in turn, cause the hearer to feel criticized and therefore to retaliate: “Why does your precious mat mean more than my innocent cat?” But if the first speaker meant the utterance purely in its locutionary sense, the relationship can get strained even though both parties believe they are uttering and understanding the same message.

Yes, language is the treasure of our species, and we could not be what we are without it. But with it we are prone to get ourselves into infinite trouble, especially since participants in most forms of human discourse are loath to metacommunicate (that is, to examine explicitly just what was meant and what was understood). This is certainly the case in the Trump-Comey interchange.

Supposing Comey’s recollection of what Trump said is correct, including the president’s use of “hope,” what exactly, or at least approximately, did he mean? And how has “hope” suddenly turned into a weasel word? (At this rate, can “faith” and “charity” be far behind?) Are Trump’s defenders correct in their interpretation, that in saying “I hope you can let this go,” the president simply meant “I look forward expectantly to your letting it go,” no more and no less? That is, is there no context suggesting that the illoctionary force of “hope” was any different from its locutionary force? Or was Comey correct in his understanding the illocutionary force of the president’s utterance as “You had better let it go, or else”? Was the remark intended as a mere expression of the president’s state of mind, period, or was it an indirect way to express the illocutionary force of a threat? Comey was certainly in a position to understand an implicit “or else,” but did Trump have that in mind? What might be Trump’s motive for engaging in the indirectness that Comey understood?

To arrive at his interpretation, Comey had to know or believe several things about the context of the comment and therefore the most likely interpretation:

1. Trump is the president of the United States, and therefore a man with a great deal of symbolic power, especially in the White House
2. Trump, as POTUS, in this situation also had a lot of actual power, i.e., the power to remove the addressee (Comey) from a position he was happy to be in (director of the FBI)
3. Trump directly firing Comey might look like, and in fact be, obstruction of justice, something Trump would want to avoid
4. Therefore, Trump was both able to (#1 and #2) and desirous of (#3) expressing his meaning indirectly, using “hope” rather than “I order you” or “I warn you” or the threatening “or else”

It is true that indirect modes of communication are very likely to be used by the less powerful to their superiors, while the latter have the ability to choose directness. But the opposite is also true. The weaker party must be indirect in order to save their hide; the more powerful may be indirect, in order to preserve their credible deniability. As always, the difference between powerful and powerless is not so much in what each can or must do, but more in who has a choice and who has none. Among the options Trump, as the more powerful party, has at his disposal is the ability to determine not only what words he can use but also what he intends them to mean. If he says “hope” means “hope,” then “hope” means “hope.” Period.

But despite his power, the president does not necessarily have the final say about what he meant. Like Comey, third-party interpreters (me, or you, or commentators on CNN or Fox News, or special counsel Robert Mueller) have had some experience with Trump, and based on our prior observations can use that information to try to divine the metamessage, the same way that the cat owner divines the mat owner’s metamessage. In this case, a third-party observer might recall that Trump has a demonstrated taste for vindictiveness, and so might make (as Comey did) reasonable assumptions about what Trump might have meant. On that basis we can agree that Comey’s interpretation of “hope” as an indirect expression of the illocutionary force of an order, warning, or threat was more likely correct, and certainly safer, than a literal interpretation. Someone does not rise to the rank of FBI director unless they are good at making, and acting on, the safer choice.

While a Trump supporter might say that Trump is a blunt talker who “tells it like it is,” and may thus interpret “hope” as meaning simply “hope,” even a reputation for bluntness doesn’t meant that someone always says exactly what they mean. Moreover, the fact that Trump had asked everyone else in the room to leave, and had repeatedly asked on other occasions whether Comey wanted to keep his job, suggests that he had ulterior motives.

So, given everything Comey knew about the power relationship between him and the president, literal and symbolic; given what he knew about the psychological nature of his interlocutor; and given what he knew as a fluent speaker of a natural human language, his interpretation was both perfectly valid and the best one for him to make. That is not to say that it is 100% correct. No one except Trump has even the possibility of knowing just what he intended by what he said. And even if he were to claim under oath that the simple locutionary force was what he intended to mean, we have no way of knowing whether that is true.